*REHOREK, SUSAN J., SAVITZKY, ALAN H., WITMER, LAWRENCE M.
(SJR) Slippery Rock University, Slippery Rock, PA 16057; (AHS) Old Dominion University, Norfolk, VA 23529; (LMW) Ohio University College of Osteopathic Medicine, Athens, OH 45701
Vasculature of the Lepidosaur nasal cavity: Do Iguanas have a bloody nose?
Previous studies on squamate cephalic vasculature focused on larger vessels leading to the nasal cavity, but rarely detailed the route of the vessels within the nasal cavity itself. Microfil -injected heads of eight juvenile green iguanas (Iguana iguana) were dissected and examined. Two additional specimens were examined using paraffin histology. The results supplement and clarify several points covered in early papers. We find that there are at least three major arteries supplying the nasal cavity: the frontal (septal and lateral nasal regions, the latter via the lateral nasal gland); the maxillary (lateral and ventral regions) and palatal (ventral region). The internal nasal cavity is a highly vascular structure, with many anastomosing vessels between terminal branches of different arteries. Such extensive internal nasal vasculature has only been described in some mammals, in which the arrangement of vessels was believed to represent a countercurrent heat exchanger. Finally, the vascular plexus in the posterior aspect of the naris is surrounded by loose connective tissue, which allows for the enlargement of the vessels, may originate from the maxillary artery. The observations clarify the vasculature of the nasal region of iguanian, but their generality among squamata will require additional comparative studies. (Session P-14, Saturday, July 7, Penn Stater, Deans Hall)

REIS, ROBERTO E.
Av. Ipiranga, 6681, Museu de Ciências e Tecnologia - PUCRS, Porto Alegre, RS 90619-900 Brazil
Taxonomy of Callichthyidae (Teleostei: Siluriformes)
Phylogenetic studies on callichthyid catfishes during the last decade have improved our current knowledge of their interrelationships. Taxonomy of subfamily Callichthyinae, which includes 12 species, if reasonably resolved. Taxonomy of subfamily Corydoradinae, however, were the bulk of species is allocated is not settled yet. Prompted by the production of Cloffsca (Check List of Freshwater Fishes of South and Central America) a carefully revised list of all nominal taxa assigned to the callichthyids was prepared. Of the 23 nominal genera eight were considered valid and of the 254 nominal species, 171 were regarded as valid. The status of some species of Corydoras and Callichthys has not been determined yet, but both groups are under taxonomic study currently. The current classification of the family Callichthyidae is compared to those of Ellis (1913) and Gosline (1940), who recognized 51 valid nominal species or subspecies and 11 genera, and 44 (9) respectively. A taxonomic history of Callichthyidae with photographs and illustrations will be presented. (Session P-24, Sunday, July 8, Penn Stater, Deans Hall)

*REIS, ROBERTO E., PEREIRA, EDSON H. L.
Av. Ipiranga, 6681, Museu de Ciências e Tecnologia - PUCRS, Porto Alegre, RS 90619-900 Brazil
Revision of the loricariid catfish genus Pareiorhaphis (Teleostei: Siluriformes)
Recent phylogenetic studies based on both anatomical and molecular evidence, demonstrated that the type species of Hemipsilichthys is not related to the bulk of species usually assigned to that genus. As a result, a major transference of species to Pareiorhaphis, the next available genus, was necessary. The species of Pareiorhaphis are revised and sixteen species are recognized as valid. Of these, only one was previously included in Pareiorhaphis and ten other are currently included in Hemipsilichthys. In addition five new species are described from coastal rivers of Santa Catarina State, from the upper Rio Uruguai basin, and from coastal drainages of northestern Rio Grande do Sul State. The monophyly of the genus Pareiorhaphis is discussed and it is diagnosed by two putative sinapomorfies: (1) the presence of soft fleshy lobes on the lateral margin of head and (2) the presence of bristle-like hypertrophied odontodes along the lateral margins of the head of adult males. With the exception of P. regani, from the Rio Negro, Amazon basin, all species of Pareiorhaphis are from the Brazilian Shield between Rio Grande do Sul and Southern Bahia. A detailed phylogenetic study of Pareiorhaphis species and all related genera is currently being conducted by one of us (EHLP). (Session P-24, Sunday, July 8, Penn Stater, Deans Hall)

RETZER, MICHAEL E.
Center for Biodiversity, Illinois Natural History Survey, Champaign, IL 61820
Changes in the fish diversity of seven drainages in Illinois, USA.
The goal of this study was to determine if there have been any changes in the species richness (the number of native and non-species) in selected river basins in Illinois. These basins were selected on the basis of data availability from three time periods: 1876-1905, 1982-1986, and 1997-1998. This study utilized data collected from surveys made in these seven basins: Des Plaines River, Kaskaskia River, Kishwaukee River, Pecatonica River, Rock River, Salt River, and Vermilion River (of the Wabash River system). Each basin showed a decline in the number of species since the 1876-1905 time period. However, since 1982-1986, four basins showed an increase in species richness. The Des Plaines River showed the greatest decline since the 1876 1905 time period but the greatest increase in species diversity since the 1982-1986 time period. Two drainages showed no change between 1982-1986 and 1997-1998. Only the Kaskaskia River has shown a decline in species richness since 1982-1986. (Session 21, Sunday, July 8, Penn Stater, Room 206, 10:30)

*REYIER, ERIC A., GILMORE, GRANT
(EAR) Dyn-2, Dynamac Corporation/ Florida Institute of Technology, Kennedy Space Center, FL 32899; (GG) Dyn-8, Dynamac Corporation, Kennedy Space Center, FL 32899
Life History Aspects of the Bigmouth sleeper Gobiomorus dormitor from east central Florida
The bigmouth sleeper Gobiomorus dormitor is one of the world's largest gobioid fishes, reaching 61 cm SL. This tropical peripheral species is a major predator in many fresh and brackish water habitats of Central America and the Caribbean. Within the United States, G. dormitor exhibits a limited distribution, having been consistently collected only in central and south Florida and in southern Texas. The purpose of this ongoing study is to investigate the distribution and dietary composition of the bigmouth sleeper within freshwater tributaries of the Indian River Lagoon, east-central Florida. Preliminary sampling indicates that this eleotrid is more abundant in upstream (predominantly oligohaline) habitats and is an important consumer of both shrimp and fish in these systems. Though spawning has not been directly observed, captures of small fry during all months suggests that reproduction is local and continuous, however, a distinct peak in fry abundance may be tied to the spring tishmishe, a pulse of shrimp and gobioid larvae that recruit to these habitats. (Session P-32, Monday, July 9, Penn Stater, Deans Hall)

RICO, CIRO
University Plain Norwich, University of East Anglia, Norfolk NR4 7TJ U.K.
Population structure and speciation modes in mbuna cichlids from Lake Malawi
This communication outlines recent evidence on the genetic structure and species diversity estimates of sympatric putative species and allopatric populations of mbuna cichlids from Lake Malawi. This evidence has allowed reaching the following conclusions: 1) Populations isolated in rocky habitat patches are genetically isolated, even at very small spatial scales. 2) Lake Malawi, in particular, contains far more endemic species of haplochromine cichlid fishes than previously thought. 3) There is no evidence that phenotypic plasticity alone explains colour variation. 4) There is no evidence for multiple origins of putative species, which differ in little more than male coloration. 5) There is substantial evidence to suggest that colour similarities of allopatric taxa reflect recent shared ancestry. 6) There is genetic evidence to suggest that allopatric populations that show male colour variation to a similar extent as reproductively isolated sympatric species may represent evolutionary units in the process of speciation. (Session 6, Saturday, July 7, Penn Stater, Pres I Hall)

*RIHERD, DAVID, VANDERGON, THOMAS L.
(DR) 18111 Nordhoff St., CSUN, Northridge, CA 91330; (TLV) 24255 Pacific Coast Highway, Pepperdine University, Malibu, CA 90263
UV-B radiation effects on photolyase gene expression during development in the California treefrog Hyla cadaverina
Ultraviolet radiation has been implicated as an effector of amphibian populations by causing DNA damage that kills or weakens embryos. A major type of UV-B induced DNA damage is cyclobutane pyrimidine dimer (CPD) formation. CPD repair involves action of CPD photolyase. Two native California treefrogs, Hyla regilla and Hyla cadaverina, appear to differ in their ability to repair CPD's. Previous studies have shown that H. regilla eggs have twice the photolyase repair activity as H. cadaverina eggs and H. cadaverina embryos die at significantly higher levels when exposed to UV-B compared to shielded embryos. To determine if H. cadaverina might alter the expression of the photolyase gene in response to UV-B, we placed fertilized eggs in natural conditions either exposed to or shielded from UV-B. The reverse transcription polymerase chain reaction was used to measure photolyase mRNA levels in developing embryos. Photolyase mRNA levels are lowest in the first day of development but increase significantly by day two. There was a significant increase in photolyase mRNA levels during development in embryos exposed to UV-B as compared to shielded embryos. These data suggest that embryos increase photolyase expression in response to exposure in an attempt at protection from damage. (Session P-14, Saturday, July 7, Penn Stater, Deans Hall)

*RIOS, NELSON, BART, HANK
Tulane University Museum of Natural History, Tulane University, Belle Chasse, LA 70037
Efficacy of Ethanol vs. Isopropanol as a fish specimen preservative
The Tulane University Fish Collection, with 7.1 million fluid-preserved specimens in over 190,000 lots, is one of the largest collections in the world and is recognized as a "National Center of Ichthyology Resource Collection". Because of the collection's high concentration on southeastern fishes, some areas of the collection have serious overflow problems. Fluid specimens in the collection are preserved in 50% isopropanol, which many in the fish collection community regard as inferior to ethyl alcohol. Over the past 6 years we have been involved in recurating the entire fish collection, including changing alcohol. Roughly 112,000 (67%) of the 167,000 lots preserved in isopropyl alcohol have been recurated to date. During the next 3 years we plan to re curate the remaining 55,000 isopropanol preserved lots. We are conducting experiments to assess the effectiveness of the alcohol transfer procedures, and modifying procedures as appropriate to increase preservation quality. These experiments involve qualitative assessments of the specimens transferred as well as quantitative measures of specimen and alcohol condition. Lots that have degenerated over time are of particular interest, and these experiments should aid in determining how to restore and/or prevent further damage of these lots. We report on preliminary results of this work. (Session P-32, Monday, July 9, Penn Stater, Deans Hall)

RITTER, ERICH K.
11517 S.W.64th Street #A, Green Marine Institute, Miami, FL 33173
Shark dive tourism: blessing or menace?
Shark dive tourism has increased dramatically in the last years and turned into a major income source for dive operations around the world. Along with this increasing popularity, questionable and unsafe habits have and led to heated debates over the meaning and dangerousness of this type of diving. A major source of problem is the "cowboy mentality" of many operations left unguided and not been backed up by scientific leadership. Shark diving has, if properly handled, a great potential in demystifying the wrongful image of sharks, and is a very important tool of applied conservation if mixed with correct information. However it is inevitable that this increasing boom must be guided and restricted by governmental agencies and other bodies to establish proper leadership, minimize risks of accidents, and maximize education. This paper focuses on the pros and cons of shark diving, its present problems caused by unqualified input, and currently established operations running a strictly scientific oriented dive operation. (Session 16, Sunday, July 8, Penn Stater, Room 207, 10:45)

RITTER, ERICH K.
11517 S.W.64th Street #A, Green Marine Institute, Miami, FL 33173
Exploratory behavior: a typical cause for accidents with white sharks, Carcharodon carcharias
Shark accidents have wrongfully been categorized by authorities and inductive generalizations, forming an erroneous picture of contact approaches by sharks. Shark accidents are multi-layered with much more potential causes than initially assumed. One of the initial reasons why some shark species bite humans is exploratory behavior. A lot of media attention is given to white shark (Carcharodon carcharias) interactions with surfers and spearfishermen. It is inevitable that shark accidents be analyzed from a deductive point of view, excluding anthropomorphism and approaches of pure theoretical nature. The goal of shark accident analysis is not the description of the outcome of an interaction - the accident - but the reasons behind it that eventually led to such an accident. This papers uses the analysis of the first ever filmed white shark accident on a diver and compares it with 10 randomly chosen white shark incidents on file where comparable injuries were found. (Session 7, Saturday, July 7, Penn Stater, Room 207, 8:00)

*RITTER, ERICH K., GORDON, IAN
(EKR) 11517 S.W.64th Street #A, Green Marine Institute, Miami, FL 33173; (IG) P.O. Box W356, Off The Edge Research, Sydney, Sydney 2100 Australia
Human induced approach behaviour on the bull shark (Carcharhinus leucas)
Approach behaviours of sharks leading to attacks on humans have been categorized in earlier years from a mostly theoretical point of view. However different shark species possess different approach behaviours due to size, sex, environment, situational circumstances and others. It is inevitable to study species individually exposing them to standardized scenarios and examine them on a intra and interspecies level. One of the major species being involved in incidents with humans is the bull shark (Carcharhinus leucas). An overview of general approach behaviour and interpretation of this species during different scenarios is given. (Session 3, Friday, July 6, Penn Stater, Room 207, 3:45)

*ROBERTS, MARK A., ANDERSON, CHRISTOPHER J., QUATTRO, JOSEPH M.
700 Sumter St, University of South Carolina, Columbia, SC 29208
Origin of in-water aggregates of loggerhead sea turtles (Chelonia mydasi) along coastal Southeastern United States
Female sea turtles rarely betray their terrestrial heritage except by coming ashore to deposit eggs; and encounters with nesting individuals provide one of the few chances for study. These logistic difficulties, combined with the complex life histories of the organisms have made sea turtles amenable to the use of genetic markers to reveal populational, ecological and evolutionary traits. Previous mitochondrial DNA (mtDNA) studies in loggerhead turtles have revealed a pattern of natal homing in females, resulting in regional genetic partitioning of this maternally inherited marker. These genetically distinct aggregates offer wildlife managers a primary target for conservation efforts by beginning to describe the management units (MU) for this species. However, aggregates of nesting females do not account for all of the points of potential human impact on sea turtles. Coastal and offshore fisheries continue to threaten sea turtle populations despite protection of nesting beaches. It is therefore increasingly necessary to understand the demography of the in water populations of sea turtles in order to properly describe MUs and establish effective management plans. Towards this end, we present a mixed stock analysis of loggerhead sea turtles encountered offshore along the southern Atlantic coast of the United States. (Session P-32, Monday, July 9, Penn Stater, Deans Hall)

*ROCHA, LUIZ A., BASS, ANNA L., ROBERTSON, D. R., BOWEN, BRIAN W.
(LAR, BWB) Department of Fisheries and Aquatic Sciences, University of Florida, Gainesville, FL 32653; (ALB) Department of Biology, SCA 110, University of South Florida, Tampa, FL 33620; (DRR) Unit 0948, Smithsonian Tropical Research Institute, APO, AA 34002
Comparative phylogeography of three surgeonfishes of the genus Acanthurus (Teleostei: Acanthuridae) from the western Atlantic
Coral reef habitats of the Atlantic are widely distributed, with large gaps between reefs in the North, South and central Atlantic. Some of these gaps are probably substantial barriers to dispersal, and may influence evolutionary processes in reef organisms. In this study we examine how these barriers influence the population structure of Acanthurus bahianus, A. chirurgus and A. coeruleus in the western and central Atlantic. The North Atlantic population of A. bahianus is distinct from western South and central Atlantic populations, indicating that the freshwater outflow of rivers in NE South America are a barrier to its dispersal. Acanthurus chirurgus and A. coeruleus showed a similar separation, but with much shalower population structure. No structure was detected within the South Atlantic, indicating that the vast oceanic distance between the Brazilian coast and islands in the central Atlantic (Ascension and St. Helena) is not a barrier to the dispersal of Acanthurus species. (Session 36, Tuesday, July 10, Penn Stater, Room 208, 9:45)

*ROE, KEVIN J., HARRIS, PHIL M., MAYDEN, RICHARD L.
425 Collections Building, The University of Alabama, Tuscaloosa, AL 35487
Molecular systematics and biogeography of the genus Ambloplites Rafinesque (Perciformes: Centrarchidae)
Ambloplites is an eastern North American genus of centrarchid fishes and consists of four species: Ambloplites constellatus Cashner and Suttkus, A. cavifrons Cope, A. ariommus Viosca, and A. rupestris (Rafinesque). Ambloplites constellatus is a species of the Ozark Uplands of northern Arkansas and southern Missouri and A. cavifrons is endemic to rivers in Virginia and North Carolina that are tributaries of Albemarle and Pamlico sounds. Ambloplites ariommus ranges from the Apalachicola River westward to the Ouachita and tribuatries of the Red River and lower White River in Arkansas and Missouri. Ambloplites rupestris is the most widespread species of the genus and is occurs naturally from Manitoba through the Great Lakes southward, west of the Appalachians to the Tennessee River drainage in Alabama and North Carolina. In this study, we used DNA sequences of the mitochondrial cytochrome b gene to generate phylogenetic hypotheses for the genus Ambloplites as part of a larger investigation into the systematics of the Centrarchidae. Specimens of Ambloplites were selected from throughout the respective species ranges, and phylogenetic hypotheses generated using the optimality criterion of parsimony. The resulting topologies will be compared to previously hypothesized relationships (e.g. Cashner and Suttkus, 1977, (Jenkins and Burkhead, 1994). (Session 28, Monday, July 9, Penn Stater, Room 208, 9:15)

*ROMERO, ALDEMARO, GREEN, STEVEN M., ROMERO, ANDREA, JEFFERY, WILLIAM R., YAMAMOTO, YOSHIYURI
(AR, AR) 1600 Grand Ave., Macalester College, St. Paul, MN 55105; (SMG) P.O.Box 249118, University of Miami, Coral Gables, FL 33124; (WRJ, YY) Department of Biology, University of Maryland, College Park, MD 20742
One eye but no vision: Blind cave Astyanax fasciatus with regenerated eyes do not respond to light.
One of the most intriguing questions in evolutionary biology is the degree to which behavior can be viewed as a consequence of morphology. We explore this issue by examining behavior associated with the loss of phenotypic structure and its presence, using responses to light by characid blind cave fish, Astyanax fasciatus, that are eyed and eyeless. Our experiments examine subjects that are epigean (eyed surface) and troglomorphic (blind cave) forms. We compare their photoresponsiveness with blind cave fish with restored eyes. These are produced transplanting the lens from an epigean fish into the optic cup of a blind cave form. The lens from the surface fish stimulates growth and development of the eye, restoring optic tissues lost during cave fish evolution. Fish were placed in an aquarium with one half illuminated with dim or bright white light or infrared light, the other half dark. Their photoresponsiveness was examined by scoring their presence in the illuminated or dark half. Preliminary results suggest that both the blind subjects and those with restored eyes are indifferent to the illumination whereas the surface forms are not. (Session 34, Tuesday, July 10, Penn Stater, Room 207, 8:30)

ROMERO, ALDEMARO, *PAULSON, KELLY M.
1600 Grand Ave., Macalester College, St. Paul, MN 55105
Scales not necessary: the evolution of scalelessness among troglomorphic fishes
Anecdotal evidence have suggested in the past that simplification or loss of scales may be one of the troglomorphic features characterizing hypogean fishes. We investigated the presence and/or absence of scales among 423 families of fishes. All families were categorized as "have scales," "do not have scales," or "mixed" (some species have scales, some do not). We could not find reliable information on the scales for 22 of them, usually small, little known families. 257 have scales (64.0%), 117 do not have scales (29.2%), and 27 were mixed (6.7%). There are 18 families of fish with troglomorphic representatives. Of those, seven (38.8%) families have scales, seven(38.8%) do not, and four (22.2%) contain both scaled and scaleless species. Our results suggest that simplification and/or loss of scales is a common feature among troglomorphic fishes but that the lack of scales in the family as a whole cannot be considered a preadaptive feature. (Session 29, Monday, July 9, Penn Stater, Room 105, 11:15)

*ROSA, RICARDO S., GRUBER, SAMUEL H., BARBOSA, ARTHUR H. D., KUENEN, MAUREEN C. E.
(RSR) Centro de Ciéncias Exatas e da Natureza, Universidade Federal da Paraiba, Joao Pessóa, PB 58059-900 Brazil; (SHG) 9300 S. W. 99th Street, University of Miami, Miami, FL 33176; (AHDB) Centro de Ciéncias Exatas e da Natureza, Universidade Federal da Paraiba, Joao Pessoa, PB 58059-900 Brazil; (MCEK) Goetoeweg #3, Curácao Sea Aquarium, Curácao, Netherlands Antilles
Diet of young lemon sharks (Negaprion brevirostris) at an isolated seamount, Atol das Rocas, Brazil.
The diet of young lemon sharks was studied in Atol das Rocas, 144 nautical miles off Natal, Brazil, based on a non-destructive, stomach eversion, sampling technique. Sharks were captured with gillnets and dipnets in an embayment of the atoll's lagoon, and subsequently anesthetized with tricaine. Stomach contents obtained through gastric eversion were preserved in isopropanol for qualitative and quantitative analyses. Eighteen sharks, total lenghts between 64.0 and 69.2 cm were sampled in March 2000. The stomachs of eight individuals were empty. One had a stomach so full that it precluded eversion. All the other nine sharks had teleost fishes in their stomachs (Albula sp., Ichthyapus sp., Synodus sp. and Sphyraena sp., as well as unidentified scales and vertebrae). Four of the sharks had cephalopod remains in their stomachs, including a possibly undescribed species of octopus. Further sampling to be conducted through the year 2001 will provide additional data on the diet of the species and on its role as an apex predator in atoll's ecosystem. (Session 17, Sunday, July 8, Penn Stater, Room 206, 8:00)

*ROSS, STEPHEN T., HEISE, RYAN J., SLACK, WILLIAM T., DUGO, MARK A.
(STR, RJH, MAD) Box 5018, University of Southern Mississippi, Hattiesburg, MS 39406; (WTS) Research and Collections Program, Mississippi Department of Wildlife, Fisheries and Parks, Jackson, MS 39202
When migratory fish don't migrate: Prolonged fresh water residency of the anadromous Gulf Sturgeon (Acipenser oxyrinchus desotoi) in the Pascagoula Drainage, Mississippi
The Gulf sturgeon, Acipenser o. desotoi, is an anadromous species that historically occurred in Gulf of Mexico drainages from Tampa Bay to the Mississippi River. In addition to several Florida populations, Gulf sturgeon persist in the Pascagoula drainage of Mississippi. Since 1997, our netting and telemetry studies have documented spring movement of adult and subadult fish into the Pascagoula River. Some fish move 236 km upstream to spawning grounds in the Bouie River, some move only 49 km into the Pascagoula River to a summer/fall holding area, and others move upstream over 130 km into the Chickasawhay River. Fish that leave the spawning area move downstream to the Pascagoula River holding area, although increasing numbers have remained at the spawning site, with residencies of 12 - 13 months in 1999 - 2000. Gulf sturgeon begin seaward migration in October and November, and downstream movement is associated with falling temperature and peaks in discharge. There is also a trend toward delayed movement of fish into salt water. Increased residency times in fresh water may be associated with declining river flow due to drought. Gulf sturgeon do not feed while in fresh water, making prolonged freshwater residency difficult to understand in terms of fitness correlates. (Session 4, Friday, July 6, Penn Stater, Room 206, 2:45)

*ROUNTREE, RODNEY A., PERKINS, PAUL J., KENNEY, ROBERT D., HINGA, KENNETH R.
(RAR) 48 Oregon Rd., UMASS-Amherst, Mashpee, MA 02649; (PJP) Wakefield, RI 02879; (RDK) Bay Campus Box 41, University of Rhode Island, Narragansett, RI 02882; (KRH) Bay Campus, Unveristy of Rhode Island, Narragansett, RI 02882
Sounds of Western North Atlantic Fishes
There is increasing interest in the potential of passive acoustics as a tool to study temporal and spatial distribution patterns, habitat use, and spawning, feeding, and predator avoidance behaviors of fishes. However, one of the primary limitations to more widespread use of passive acoustics in studies of fish ecology is the lack of well documented, and readily available, sound references. This has led to our efforts to recover and make available a digital copy of a tape of fish sounds that originally accompanied the landmark book "Sounds of Western North Atlantic Fishes" by Marie Fish and William Mowbray. They examined over 220 species from 59 families, and found biological sounds from 153 species from 36 families. The creation and distribution of a CD of fish sounds is the first step in a larger effort to rescue over 3 decades of sounds recorded at the Narragansett Marine Laboratory (Now the Graduate School of Oceanography at the University of Rhode Island), as well as other historical data, and establish a National Archive of Fish Sounds at Cornell University. In this presentation we provide audio samples of fish sounds from the CD and present a summary of ongoing efforts to create the National Archive. (Session P-32, Monday, July 9, Penn Stater, Deans Hall)

RUBBO, MICHAEL J.
208 Mueller Lab, The Pennsylvania State University, University Park, PA 16802
Evidence for Invertebrate/Vertebrate Intraguild Predation: Cursorial Spiders Act as Predators of Vertebrates
The interactions between invertebrates and vertebrates in terrestrial systems remain largely unexplored. We found that wolf spiders (Araneae, Lycosidae) have the ability to prey upon both juvenile spotted salamanders (Ambystoma maculatum), and juvenile ground skinks (Scincella lateralis). Moreover, we found skinks to employ antipredatory behaviors (i.e., immobility) in the presence of the chemical cues of wolf spiders, thus providing evidence that skinks recognize wolf spiders as predators prior to an encounter. These data indicate that wolf spiders and small terrestrial vertebrates may interact in ecologically meaningful manners.

We hypothesize that the relationship between these taxa is a type of intraguild predation (IGP). Skinks and salamanders both feed upon small wolf spiders, thus the predatory relationship appears to be reciprocated by the vertebrates. The IGP relationship exhibited by these taxa most likely incorporates an ontogenetic shift whereby adults of one taxa feed upon the juveniles of the other until the juveniles reach a size where predation is no longer possible. This research demonstrates a new link in the food web of the forest floor, and indicates that cursorial spiders may occupy a significantly different trophic status than traditionally believed. (Session 22, Sunday, July 8, Penn Stater, Room 206, 2:00)

*RUBER, LUKAS, BRITZ, RALF, NG, PETER K. L., ZARDOYA, RAFAEL
(LR, RZ) Jose Gutierrez Abascal 2, Museo Nacional de Ciencias Naturales, Madrid, 28006 Spain; (RB) Auf der Morgenstelle 28, Universitaet Tuebingen, Tuebingen, 72076 Germany; (PKLN) Kent Ridge, National University of Singapore, Singapore, 119260 Republic of Singapore
Molecular phylogeny of the fighting fish genus Betta: insights into the evolution of breeding behavior and Southeast Asian biogeography
The fighting fish genus Betta (Belontiidae, Anabantoidei) with approximately 50 described species is the most specious genus among anabantoids. About 1/3 of the species construct bubble nests in which the eggs are spawned whereas the other species are mouthbrooders. Previous ethological data suggested extensive parallel evolution of mouthbrooding in the genus; however, this hypothesis is not supported by more recent morphological data based on egg surface structure, which indicated the monophyly of mouthbrooders based on shared derived characters. The distribution of the genus Betta includes the Indo-Chinese peninsula, the Malay Peninsula, and the Indo Malayan archipelago west of Wallace's line. Southeast Asia has been a focus of zoogeographic interest since the work of Wallace in 1876. The genus Betta with many species endemic to single islands or drainage systems is an ideal group to test current hypotheses about Southeast Asian biogeography. Given the current lack of consensus regarding phylogenetic relationships we present a molecular phylogeny based on complete cytochrome b sequence data to study the evolution of breeding behavior and phylogeographic patterns in the fighting fish genus Betta. (Session 28, Monday, July 9, Penn Stater, Room 208, 11:30)

RUFFING, RENEA A.
Room 9 Ferguson Building, The Pennsylvania State University, University Park, PA 16802
A Systematic Analysis of the Metriaclima c.f. livingstonii Complex from the South East Arm of Lake Malawi, Africa
The rapid evolution of the family Cichlidae makes discrimination among these fishes difficult, leaving many species improperly classified or undescribed. This investigation examined described species in the Metriaclima c.f. livingstonii complex and determined their relationships to six phenotypically similar allopatric populations. Morphometric and meristic data from six allopatric populations from Mazinzi Reef, Namiasa Point, Mpandi Island, Lake Malombe, Maleri Island, and Crocodile Rocks, the Metriaclima livingstonii holotype, M. lanisticola syntypes and a population from Cape Maclear were analyzed using sheared principal component analysis. Allopatric populations from Lake Malombe, Maleri Island, Namiasa Point, and Crocodile Rocks formed a clinal gradient. They were different from the type specimens, and other populations and were described as one new polytypic species. The populations from Mazinzi Reef and Mpandi Island were found to be different from all other populations and were described as new species. The population from Cape Maclear overlapped with the M. lanisticola types indicating they are conspecific. Because no locality information is available for the M. livingstonii holotype, and its relationship with other fishes in this group cannot be determined, I am restricting the name Metriaclima livingstonii to the specimen stored in the British Museum of Natural History. (Session 18, Sunday, July 8, Penn Stater, Room 208, 9:00)

RUHNKE, TIM
West Virginia State College Institute, WV 25112
The peculiar cestode fauna of alopiid sharks
Alopias pelagicus and A. superciliosus are parasitized by species of Litobothrium, a morphologically unique genus of tapeworms found exclusively in selected lamniform shark species. These shark species are also host to tapeworms of the genera Marsupiobothrium and Paraorygmatobothrium. In addition, a cestode of unknown taxonomic affinity has been collected from A. pelagicus. The cestode fauna of A. vulpinus differs from the former two species. Litobothrium is absent from A. vulpinus, and immature specimens of cestode genera commonly parasitic in lamnid sharks and carcharhinid sharks have been collected from Alopias vulpinus. Paraorygmatobothrium exiguum has been found in A. vulpinus from the Atlantic and Pacific oceans. A species each from the genera Pithophorus and Paraorygmatobothrium have also been described from A. vulpinus, collected from the Pacific ocean. Molecular phylogenetic analyses of the cestode genera Litobothrium, Marsupiobothrium, Paraorygmatobothrium, the unknown cestode, and a number of other elasmobranch tapeworm species indicate the following: 1. the "native" cestode fauna of alopiid sharks may be relictual in nature, and 2. other species clearly have been borrowed several times from a cestode clade evolutionarily linked to carharhiniform sharks. (Session 10, Saturday, July 7, Penn Stater, Room 207, 2:45)

RUNKLE, STEPHANIE, HILL, JULIE, KANTOROW, MARC, HORWITZ, JOSEPH, *POSNER, MASON
(SR, JH, MP) 401 College Avenue, Ashland University, Ashland, OH 44805; (MK) Department of Biology, West Virginia University, Morgantown, WV 26505; (JH) 100 Stein Plaza, Jules Stein Eye Institute, UCLA School of Medicine, Los Angeles, CA 90024
Differential expression and chaperone function of the small heat shock protein alpha crystallin in the zebrafish, Danio rerio
Alpha crystallin is a small heat shock protein found in the ocular lens of all vertebrate taxa. As a structural protein it contributes to the refractive properties of the lens. Yet in mammals it has also been shown to function as a molecular chaperone, preventing the stress-induced aggregation of proteins that would otherwise cloud the lens. There has been no study of this chaperone function in ectothermic taxa. Here we report the sequences and expression patterns for both subunits (A and B) of zebrafish alpha crystallin, and present the first data on chaperone function of alpha B-crystallin from a non mammalian vertebrate. Amino acid substitutions in zebrafish alpha B-crystallin at mammalian phosphorylation sites suggest differences in chaperone function. Semi-quantitative RT-PCR and Northern blot analysis showed that alpha B crystallin expression was limited to the zebrafish lens. Assays for chaperone function indicated that zebrafish alpha B-crystallin is 20% less effective preventing the heat-induced aggregation of a target protein compared to its mammalian orthologue. Collectively these data indicate that zebrafish alpha crystallin plays less of a chaperone role than its mammalian orthologue. This research is a first step towards investigating the changing role of alpha crystallin during vertebrate evolution. (Session 19, Sunday, July 8, Penn Stater, Room 105, 9:00)

*RYDENE, DAVID A., GILMORE, RICHARD G.
Mailcode DYN-8, Dynamac Corp., Kennedy Space Center, FL 32899
Microhabitat selection by juvenile spotted seatrout: substrate preferences and predator influence
The spotted seatrout, Cynoscion nebulosus, is generally considered a species whose juveniles are seagrass-associated. However, beyond this little is known of their microhabitat preferences or the driving forces behind such preferences. Wild-caught juvenile seatrout (26-82 mm SL, mean=50 mm)were placed individually into round fiberglass tanks (tank diameter=122cm) containing 3 equally available substrate types: bare sand, low-density artificial seagrass, and medium-density artificial seagrass. During each trial, the location of a seatrout in a tank was observed and recorded every 3 minutes for a 1 hour period. A different seatrout was used for each trial. Sixty-three trials were run with a predator (common snook Centropomus undecimalis, 227-242 mm SL) present in the tank with the seatrout and another 63 trials run with no predator present. Analyses using Friedman's repeated measures ANOVA on ranks indicated that juvenile seatrout exhibited no significant substrate preferences when the predator was absent (p=0.08), but spent significantly more time in low and medium-density seagrass vs. bare sand when the predator was present in the tank (p=0.0005). Microhabitat preferences will also be discussed in terms of juvenile seatrout data from field collections made in the Banana River and Mosquito Lagoon, Florida. (Session27, Monday, July 9, Penn Stater, Room 206, 9:15)

*SABAJ, MARK H., FERRARIS, CARL J.
(MHS) 1900 Benjamin Franklin Parkway, Academy of Natural Sciences, Philadelphia, PA 19103; (CJF) 2944 NE Couch St., California Academy of Sciences, Portland, OR 97232
Taxonomy of the Doradidae (Siluriformes)
Ongoing taxonomic studies on the 128 nominal species (41 nomimal genera) of Neotropical thorny catfishes (Siluriformes: Doradidae) resolved the family into 72 valid species in 30 genera. The status of six nominal species has not been determined because type specimens were not examined (Amblydoras truncatus Bleeker, Doras insculptus Miranda-Ribeiro, Doras polygramma Kner, Oxydoras holdeni Fernández-Yépez, Oxydoras steindachneri Perugia) or because types do not exist and application of the name requires further study (Doras castaneoventris Jardine). These six names were treated as species inquirienda and may result in additional valid taxa or effect further name changes. This study resulted in the discovery of previously unrecognized types and corrections to the publication date and authorship for several species. The newly proposed taxonomy was compared with those of Higuchi (1992) and Eigenmann (1925) who recognized 70 valid species (30 genera) and 68 (26) respectively. A taxonomic history of the Doradidae will be presented together with photographs and illustrations of many of the included species. (Session P-24, Sunday, July 8, Penn Stater, Deans Hall)

SASKO, DESIRÉE, *MOTTA, PHILIP J.
(DS) 250 Tequesta Dr., Suite 304, Perry Institute for Marine Science/Caribbean Marine Research Center, Tequesta, FL 33469; (PJM) 4202 E Fowler Ave, SCA 110, University of South Florida, Tampa, FL 33620
The excavation kinematics and feeding-ventilatory coupling of the Atlantic cownose ray, Rhinoptera bonasus.
This study explores the feeding behavior and mechanics of a myliobatid, the Atlantic cownose ray Rhinoptera bonasus. High-speed videography was used to determine the prey excavation and capture kinematics of Rhinoptera bonasus. Videography and dye extraction were used to determine feeding behavior and water flow patterns during prey capture in the lab and in situ. Prey excavation involves repeated jaw opening and closing movements resulting in fluidization of the sand to uncover the benthic prey. Inertial suction prey capture during the preparatory phase is characterized by depression of the subrostral lobes and a slight closure of the jaws. The expansive phase begins with the closure of the spiracle, followed by depression of the mandible and protrusion of the palatoquadrate and nasal cartilages. During the compressive phase, the mandible is elevated toward the palatoquadrate and nasal cartilages grasping the prey. In the recovery phase, the jaws are brought back to a resting position and the spiracle is reopened. Thus, the feeding and ventilatory movements are coupled in time such that the ray only brings in water through the mouth during food capture. (Session P-14, Saturday, July 7, Penn Stater, Deans Hall)

*SASKO, DESIRÉE, MOTTA, DR. PHILIP J.
(DS) 250 Tequesta Dr., Suite 304, Perry Institute for Marine Science/Caribbean Marine Research Center, Tequesta, FL 33469; (DJM) 4202 E Fowler Ave, SCA 110, University of South Florida, Tampa, FL 33620
The excavation kinematics and feeding-ventilatory coupling of the Atlantic cownose ray, Rhinoptera bonasus.
This study explores the feeding behavior and mechanics of a myliobatid, the Atlantic cownose ray Rhinoptera bonasus . High-speed videography was used to determine the prey excavation and capture kinematics of Rhinoptera bonasus. Videography and dye extraction were used to determine feeding behavior and water flow patterns during prey capture in the lab and in situ. Prey excavation involves repeated jaw opening and closing movements resulting in fluidization of the sand to uncover the benthic prey. Inertial suction prey capture during the preparatory phase is characterized by depression of the subrostral lobes and a slight closure of the jaws. The expansive phase begins with the closure of the spiracle, followed by depression of the mandible and protrusion of the palatoquadrate and nasal cartilages. During the compressive phase, the mandible is elevated toward the palatoquadrate and nasal cartilages grasping the prey. In the recovery phase, the jaws are brought back to a resting position and the spiracle is reopened. Thus, the feeding and ventilatory movements are coupled in time such that the ray only brings in water through the mouth during food capture. (Session P-14, Saturday, July 7, Penn Stater, Deans Hall)

*SATO, TETSU, MIZOIRI, SHINJI, TABORSKY, MICHAEL, MWAFLIRWA, DAVIE
(TS) 494-59 Chogano, Minami-Izu Marine Ecology Lab, Minami-Izu, Shizuoka 415 0314 Japan; (SM) P. O. Box 280, University of Malawi, Zomba, Zomba Malawi; (MT) Wohlenstrasse 50a, University of Bern, Hinterkappelen, Bern CH-3032 Switzerland; (DM) P. O. Box 30133, Lake Malawi National Park, Lilongwe 3, Lilongwe Malawi
Breeding nests of substrate brooders as a resource for inter-specific reproductive activities among cichlids of Lakes Tanganyika and Malawi.
The nests of substrate brooding fishes are a resource for reproduction of other species. The nests of host species provide extra spawning substrates for the guest species, and serve as a safe refuge of guest young. Young of the guest species is either spawned at the host nest or carried into it by their parent(s), or the free-swimming young swims to the host nest by themselves. Adoption of foreign broods is generally considered advantageous to the host, although it bears both benefits and costs to the hosts.

In Lake Tanganyika, the nest of a shell-brooding cichlid, Lamprologus callipterus, is utilized by several cichlids as a spawning and brooding site. In Lake Malawi, the nest of a substrate brooding catfish, Bagrus meridionalis, is associated with free-swimming cichlid young that take advantages of guarding by this large catfish. In the former, all guests are substrate brooders that spawn in the host nest, while all guests in the latter are mouthbrooders that join the host nest after they become free-swimming. We will make a comparison of costs and benefits of adoption of guest broods between these two systems to clarify complex interactions between hosts and two different types of guest species. (Session 25, Monday, July 9, Penn Stater, Pres I Hall)

*SCHAEFER, SCOTT A., AQUINO, ADRIANA E.
Dept. of Ichthyology, American Museum of Natural History, New York, NY 10024
Structural diversity in the temporal cranium of catfishes: phylogenetic and functional implications
Morphology of the temporal cranium, postotic laterosensory canal, and posterior lateral-line nerve was surveyed across loricarioid and outgroup catfishes to resolve conflicting statements regarding homology and significance of intrinsic variation. Astroblepids, callichthyids, loricariids and scoloplacids differ from Nematogenys, other trichomycterids, and non loricarioid catfishes in having a reduced number of temporal region bones. Loricariids share with astroblepids and some trichomycterids presence of direct contact between the trunk lateral-line canal and swimbladder capsule chamber; however, only loricariids have the lateralis canal in direct contact with the swimbladder membrane, resulting in an additional laterophysic connection. Derived trichomycterids share with outgroup amphiliids, plotosids and sisorids a cranial exit of the posterior lateral-line nerve separate from that of the vagus nerve, whereas both nerves exit the cranium via a common foramen in other loricarioids and outgroup catfishes. Callichthyids share with scoloplacids and loricariids a lateral-line nerve pathway within the swimbladder capsule. Loricariids have a derived double-layered pterotic bone with postotic canal in the ventral layer. Based on the previously well established scheme of interrelationships among loricarioid families, we infer that much of the variation in temporal cranial morphology over the course of loricarioid evolution has involved independent convergence toward increased functional integration of primitively separate structures within the octavolateralis system. (Session 29, Monday, July 9, Penn Stater, Room 105, 10:30)

*SCHREY, AARON W., HEIST, EDWARD J.
Fisheries and Illinois Aquaculture Center, Southern Illinois University, Carbondale, IL 62901
Genetic Structure Analysis of the Shortfin Mako (Isurus oxyrinchus) from Multiple Microsatellite Loci.
We investigated genetic population structure in the shortfin mako shark using multiple microsatellite markers. A previous study, which utilized restriction fragment length polymorphism of mitochondrial DNA, found significant structure. We developed several microsatellite loci by screening a sub-genomic library for di-, tri-, and tetra-nucleotide repeats. Positive clones were sequenced and primers for the polymerase chain reaction were designed. Primers that amplified polymorphic loci were used to genotype samples from four oceans (N. Atlantic, S. Atlantic, N. Pacific, and S. Pacific) via polyacrylamide gel electrophoresis. Analyses of Molecular Variance (AMOVA) results show lower levels of genetic divergence than expected. Primers developed were tested for possible cross-species amplification in several other species of sharks. The markers may be useful for studies in species including white sharks (Carcharodon carcharias), thresher sharks (Alopias spp.) and porbeagle (Lamna nasus). (Session 3, Friday, July 6, Penn Stater, Room 207, 4:15

*SCHULTZ, ERIC T., MARTIN, JENNIFER M., LWIZA, KAMAZIMA M. M.
(ETS, JMM) 75 N. Eagleville Rd., University of Connecticut, Storrs, CT 06269; (KMML) Marine Sciences Research Center, State University of New York, Stony Brook, NY 11794
Riding the salt: tide, depth, and lateral position effects on the concentration of larval bay anchovy (Anchoa mitchilli) in the Hudson River Estuary
In estuaries, there is often retention or net movement of larvae in an up estuary direction, against the mean flow. We are addressing how estuarine circulation and larval behaviors serve to transport larvae of the bay anchovy (Anchoa mitchilli), which have been reported to display net up-estuary larval movements. We conducted two cruises of 3 days each in the Hudson River estuary, surveying ichthyoplankton abundance, salinity, and current. Intensive sampling (every 2 hours) in one section of the river was designed to permit tests of time, depth, and lateral position (east and west shoals, channel) on larval concentration. The cruises were 1 week apart, enabling us to examine neap/spring tidal effects. With data on larval size, we were able to test for ontogenetic changes in larval distribution. Anchovy larvae were more concentrated at greater depths. Tidal cycles in concentration at all depths indicate periodic vertical movements; these movements are upward during periods of tidal flow, and downward during periods of slack water. Turbulent mixing can reduce the tendency of larvae to concentrate at depth; during spring tide conditions, the depth and tidal effects were greatly reduced. We predict that upriver transport will be most rapid during neap tide periods. (Session 4, Friday, July 6, Penn Stater, Room 206, 1:30)

SCHWEIGERT, SCOTT A.
229 Arts Building, The Pennsylvania State University, University Park, PA 16802
Images of rays and sharks in seventeenth-century European art
>From the 1570s to the close of the seventeenth century, artists in Italy and the Low Countries produced a substantial number of still life paintings representing the "bounties of the ocean." Whether within the context of fish stalls at local markets, kitchen interiors, or heaping piles of specimens carefully arranged on shore, the demand for and profusion of these images in early modern Europe raises a host of cultural and anthropological questions. Marine paintings in which rays and, less frequently, sharks figure prominently have been interpreted as lavish displays of abundance and wealth. Working from Neapolitan, Dutch and Flemish examples, this paper sheds light on the significance of sea animals as commodities in seventeenth-century economies. Perhaps more revealingly, my study examines images of these creatures as emblems of abundance in the context of European seaport and fishing centers where they functioned as important elements of the "cult of the sea." (Session 26, Monday, July 9, Penn Stater, Room 207, 10:30)

*SEARS, MICHAEL W., ANGILLETTA, MICHAEL J.
(MWS) Biological Resources Research Center, University of Nevada, Reno, NV 89557; (MJA) Department of Life Sciences, Indiana State University, Terre Haute, IN 47809
Phenotypic plasticity of life history in the sagebrush lizard (Sceloporus graciosus)
Geographic variation in life histories is common among lizards. A long-term study of sagebrush lizards (Sceloporus graciosus) in southern Utah has revealed that lizards from high elevations exhibit faster growth and reduced maintenance metabolism compared to lower elevation lizards. A laboratory common garden experiment was performed using hatchling lizards from three populations to determine genetic and environmental sources of variation in life history. Hatchlings were raised from field-caught gravid females. Hatchlings were fed ad libidum and were randomly assigned to a water treatment group. Growth rates and metabolic rates were measured for 30 days after hatching. When controlled for food intake, hatchlings did not differ in growth with respect to length regardless of source population or water treatment. Growth in body mass did not differ among source populations, but did differ between water treatments. Water supplementation affected body mass by elevating hydration state, as hatchling dry masses did not differ. Metabolic rates of hatchlings did not differ over the course of the experiment, regardless of source population or water treatment. These results indicate that variation in life histories for these populations are due to environmental variability in resources and acclimation of physiology, and not due to genetic differentiation among populations. (Session 4, Friday, July 6, Penn Stater, Room 206, 4:15)

*SECOR, CAROL L., DOWLING, THOMAS E.
Department of Biology, Arizona State University, Tempe, AZ 85287
Biogeography and molecular phylogenetics of western North American mountain suckers
The mountain suckers, a group of western North American fishes in the family Catostomidae, contains five recognized species (Catostomus clarki, C. discobolus, C. platyrhynchus, C. plebeius, and C. santaanae). In this study, we describe relationships within the group at inter- and intraspecific levels using phylogenetic analysis of sequence data from three mitochondrial genes (ND4l, cytb, and ND2). While phylogenetic relationships based on morphology have been described, variation within some of these species is considerable. Our sampling regime was designed to assess levels of variation within several of these species and to contrast relationships derived from our sequence data with hypotheses of relationships expected from morphological characters and geological history. While some relationships were concordant with morphological characters, others were not. For example, the basal placement of C. santaanae and one highly divergent C. platyrhynchus lineage within the tree was inconsistent with predictions made from both morphological and geological evidence. We also found multiple lineages in samples of C. platyrhynchus and C. discobolus from different geographic regions. Some, but not all of these unique lineages were predicted from previously described patterns of intraspecific morphological variation. (Session 36, Tuesday, July 10, Penn Stater, Room 208, 8:45)

*SEEHAUSEN, OLE, MAAN, MARTINE, MROSSO, HILARY D. J., VAN ALPHEN, JACQUES J. M.
(OS) University of Hull, Hull, Yorkshire HU6 7RX U.K .; (MM) P.O. Box 9515, University of Leiden, Leiden, 2300RA The Netherlands; (HDJM, JJMv) P.O. Box 9516, University of Leiden, Leiden, 2300RA The Netherlands
Investigations into the nature of selective forces that cause mate choice in cichlid fish
Many (us included) believe that sexual selection is a major force behind evolutionary changes between and within populations of Great Lake cichlids. However, very little is known about the mechanisms. There are few investigations into intraspecific sexual selection upon the characters associated with speciation in these fish. There are even fewer investigations into the nature of the evolutionary forces that cause and direct selective mate choice. We investigate correlates of mating preferences in two species of Lake Victoria cichlids that represent models for two very different mechanisms of population diversification and possibly speciation. We hope to elucidate mechanisms that may apply to many other species of Great Lake Cichlids too. (Session 15, Sunday, July 8, Penn Stater, Pres I Hall)

*SHERMAN, ELIZABETH, LEVITIS, DANIEL
Bennington College, Bennington, VT 05201
Heat induced changes in thermal tolerance as a function of developmental stage in larval and juvenile Bufo americanus and Xenopus laevis.
In response to a brief heat stress, many ectotherms exhibit elevated levels of thermal tolerance. We studied this phenomenon in tadpoles and juveniles of the temperate Bufo americanus and the tropical Xenopus laevis. Animals were heated and then held for 10 minutes at 4o C below the average thermal tolerance of premetamorphic tadpoles (37o C for B. americanus and 32o C for X. laevis). Following a two hour room temperature interval, the critical thermal tolerances (CTMs) of pretreated animals were determined and compared to those of controls. Premetamorphic tadpoles (Gosner stages 26-43) of both species exhibited an increase in thermal tolerance following heat pretreatment compared to control tadpoles. In both species the tadpole stages exhibiting the greatest increase in CTM were 42-43. However, during metamorphosis (stages 44-45) B. americanus tadpoles exhibited a decrease in CTM following pretreatment while X. laevis tadpoles still exhibited an increase. This may reflect the more stressful nature of the more rapid metamorphosis of Bufo. The CTMs of animals of both species that had just completed metamorphosis (stage 46) did not change after pretreatment while that of juveniles of both species increased. These results are examined in light of the various mechanisms underlying metamorphosis of the two species. Supported by NSF OSR-9350540. (Session P-14, Saturday, July 7, Penn Stater, Deans Hall)

*SIMONS, ANDREW M., JOHNS, MALCOLM E., WOOD, ROBERT M.
(AMS, MEJ) 200 Hodson Hall, University of Minnesota, St. Paul, MN 55108; (RMW) 3507 Laclede, Saint Louis University, St. Louis, MO 63103
Phylogeography of the Fundulus catenatus species group.
The studfish, Fundulus catenatus is restricted primarily to the Highlands of the southeastern United States with relict populations in Indiana and western Mississippi. The distribution of this taxon is consistent with the Highlands Vicariance hypothesis and was used as supporting evidence for this hypothesis by Mayden (1988). Previous studies of phylogenetic relationships among F. catenatus populations indicated that some populations have relationships that are inconsistent with the Highlands Vicariance hypothesis (Grady et al. 1990; Strange and Burr 1997). We examined phylogenetic relationships among 21 populations based on mitochondrial cytochrome b sequences. Fundulus bifax and F. stellifer were also included in the analysis. Fundulus notatus, F. olivaceous, and F. bifax were used as outgroups. Recovered phylogenetic patterns are not consistent with the Highlands Vicariance hypothesis or previous hypotheses of relationship for this group. Fundulus catenatus was paraphyletic with respect to F. stellifer and F. bifax, indicating existence of an undescribed taxon in Tennessee. Ouachita Highland taxa are monophyletic, sister to taxa in Ozark, Ohio, and Cumberland drainages. These are sister to Tennessee River F. catenatus plus F. bifax and F. stellifer. Low divergence among populations are more consistent with dispersal rather than a vicariance hypothesis. (Session 36, Tuesday, July 10, Penn Stater, Room 208, 9:15)

*SIMPFENDORFER, COLIN A., BURGESS, GEORGE
(CAS) 1600 Ken Thompson Parkway, Mote Marine Laboratory, Sarasota, FL 34236; (GB) PO Box 117800, University of Florida, Gainesville, FL 32611
Status of the Atlantic sharpnose shark (Rhizoprionodon terraenovae) US waters: results of preliminary analysis using an age-structured model.
Landings of small coastal sharks, and especially the Atlantic sharpnose shark (Rhizoprionodon terraenovae), have increased in US waters as populations of large coastal species have declined. We are assessing the impact of fishing on R. terraenovae using an age-structured population model. A Bayesian approach to the assessment is used to incorporate both prior information about this and other species, and uncertainty about the data and population processes. Rhizoprionodon terraenovae is caught in a wide variety of fisheries, including the shark longline fishery, drift gillnet fishery, menhaden purse-seine fishery, shrimp trawl fishery, coastal gillnet fisheries, recreational fisheries, head boat fisheries, and many others. This diversity of fisheries makes the assessment more difficult. Data on the biology, gear selectivity, landing and discard practices, and population structure are included in the model. We present the preliminary results from the assessment for R. terraenovae. Difficulties with the assessment are discussed, and avenues for future research to improve the assessment are identified. (Session 3, Friday, July 6, Penn Stater, Room 207, 2:00)

*SIMPFENDORFER, COLIN A., CASTRO, JOSE I.
(CAS) 1600 Ken Thompson Parkway, Mote Marine Laboratory, Sarasota, FL 34236; (JIC) Mote Marine Laboratory, National Marine Fisheries Service, Sarasota, FL 34236
Habitat issues in the conservation of smalltooth sawfish (Pristis pectinata)
Smalltooth sawfish (Pristis pectinata) are critically endangered in the western Atlantic, and are currently being considered for inclusion on the US Endangered Species List. Recovery of the sawfish population will depend upon reducing fishing mortality and providing sufficient suitable habitat. Information on the current distribution of P. pectinata was gathered from the public and research surveys. The results of this study have identified several human-mediated habitat issues in the conservation of sawfish. These include the use of canal developments as alternative habitat, and the use of power station outflows as thermal refuges during winter. The importance of these issues is discussed and future research directions suggested to further understand their impact. (Session 16, Sunday, July 8, Penn Stater, Room 207, 9:45)

*SKOMAL, GREGORY B., BENZ, GEORGE W.
(GBS) P.O. Box 68, Massachusetts Division of Marine Fisheries, Vineyard Haven, MA 02568; (GWB) One Broad St., Tennessee Aquarium, Chattanooga, TN 37401
Sharks under Arctic ice: acoustic tracking of Greenland sharks, Somniosus microcephalus
In May 1999, six Greenland sharks (Somniosus microcephalus) were tracked off northern Baffin Island, Nunavut, Canada to determine if vertical and horizontal movements were indicative of seal hunting behavior. Six Greenland sharks in the size range of 190-355 cm fork length were caught on lines baited with seal meat, then tagged with depth sensitive individually coded ultrasonic transmitters and tracked for 5.5-31.4 h. Horizontal and vertical movements were determined from data collected by manual tracking with a directional hydrophone and by five remote receivers set in a listening array. Horizontal rates of movement were found to differ significantly (p< 0.01) among sharks and ranged from 0.015 to 0.463 m s ± 1, with a mean of 0.217 m s ± 1. Rates of descent for the six tracked sharks were significantly (p<0.01) higher than rates of ascent. The sharks exhibited no apparent depth or temperature preference and during 31%, 26%, and 42% of the total aggregate tracking time, they were 0-70 m, 70-170 m, and 170-280 m deep, respectively. Pooled data for the six sharks indicated nocturnal movement into shallower depths. This study demonstrated that Greenland sharks are not exclusively benthic sharks and may actively hunt ringed seals just under landfast sea ice. (Session 10, Saturday, July 7, Penn Stater, Room 207, 11:00)

*SLOSS, BRIAN L., BILLINGTON, NEIL, BURR, BROOKS M.
(BLS) Fisheries and IL Aquaculture Center, Southern Illinois University, Carbondale, IL 62901; (NB) 213 McCall Hall, Troy State University, Troy, AL 36081; (BMB) Dept. of Zoology, Southern Illinois University, Carbondale, IL 62901
Phylogenetic relationships within the Percidae based on the analysis of two mitochondrial DNA genes
Percidae (Order Perciformes) is among the most speciose families of northern hemisphere fishes with over 175 North American species in six genera and 14 Eurasian species in six genera. Phylogenetic relationships among percids have been investigated by numerous authors. A lack of informative characters, poor taxonomic sampling, and/or conflicting data have hampered previous studies. To improve resolution of intrafamilial relationships, mitochondrial DNA sequence data from the 12S rRNA and cytochrome b genes of 51 percid species (nine of 10 genera and all but two subgenera of darters) were used to infer relationships within the family.

Four major lineages were recovered, Etheostomatinae, Luciopercinae, Perca, and Gymnocephalus. Monophyly of the genera was consistently resolved for all but Etheostoma and Zingel. The subfamily Percinae, which historically includes Gymnocephalus and Perca, was not resolved. Perca species showed a highly resolved sister relationship between P. flavescens and P. schrenki. The independent origin of small, benthic stream fishes on both continents (North American darters and Eurasian Zingel and Romanichthys) was strongly supported. The inability to consistently resolve sister relationships among the four major percid lineages and within the darters may be the result of rapid diversification within the family. (Session 28, Monday, July 9, Penn Stater, Room 208, 11:15)

*SMITH, DARRYL, HORN, MICHAEL
800 N. State College Blvd., California State University, Fullerton, Fullerton, CA 92834
Trophic position of southern California estuarine and island populations of the silverside fish Atherinops affinis (Teleostei: Atherinopsidae): analyses of 15 N and 13 C stable isotopes and dietary items.
The silverside fish Atherinops affinis (Teleostei: Atherinopsidae) is an abundant fish species of the eastern north Pacific. During summer months, A. affinis are a component of various sea bird diets, and, therefore, play an important role in the flow of energy, nutrients, and contaminants through marine communities. The feeding strategy of A. affinis appears to be one of an opportunistic omnivore; prior dietary studies have noted differences in diet based principally on habitat but also on season and fish age. We sought to clarify exact role of A. affinis in the southern California marine food web during one summer by comparing the trophic position of estuarine and island populations though analyses of stable isotopes (15 N and 13 C) and dietary items. A. affinis differed in trophic position between estuarine and island sites with the estuarine fish feeding more on macroalgae and detritus and the island fish feeding more on zooplankton. Our findings support the notion that A. affinis is an opportunistic omnivore. (Session 17, Sunday, July 8, Penn Stater, Room 206, 9:00)

*SMITH, GERALD R., DOWLING, TOM
(GRS) Museum of Zoology, University of Michigan, Ann Arbor, MI 48109; (TD) Department of Biology, Arizona State University, Tempe, AZ 85287
Resolution of Incongruent Morphological, Molecular, and Paleontological Data on Phylogeny of Catostomid Fishes.
Mitochondrial and nuclear DNA sequence data for catostomid phylogenies disagree with morphological and paleontological data. We expected that molecular data would refine our phylogenetic estimates, but the results are so discordant that major errors are indicated. If molecular data are correct, recognized genera of western catostomids are polyphyletic at each of several localities or, as has been suggested, the "genera" Chasmistes and Deltistes represent lake-adapted trophic polymorphisms that occur in several species of Catostomus. The alternative hypothesis, that introgression of molecular sequences has occurred repeatedly in these fishes, is tested with additional sequence data, morphological homologies in the fossil record, and development in diverse modern habitats. The fossil record of these genera dates back at least 6 million years, supported by numerous characters in fossils from many localities. Pliocene distributions suggest a single origin of Chasmistes followed by radiation of several species. The trophic polymorphism hypothesis is rejected because the genera breed true in hatcheries and in transplants in diverse habitats (e.g., rivers and reservoirs). Mitochondrial and nuclear DNA transfer by intogression in Catostomus, Chasmistes, and Deltistes is the preferred explanation. (Session P-24, Sunday, July 8, Penn Stater, Deans Hall)

SMITH, W. L.
American Museum of Natural History, New York, NY 10024
Phylogenetic Systematics of the Pacific Sculpins of the Genus Icelinus
The cottid genus Icelinus contains nine described species from the North Pacific Ocean and one undescribed species from California. The genus was erected by Jordan in 1885 for Icelinus quadriseriatus and was expanded to five species following descriptions by Gilbert (1890, 1896) and Evermann and Goldsborough (1907) of four species obtained during the Albatross cruises. Bolin (1936) revised Icelinus and synonymized it with the genus Tarandichthys, bringing the total to eight species. In 1980, Yabe, Tsumura, and Katayama described a ninth species, Icelinus japonicus, from the Sea of Japan. This study tested the monophyly of Icelinus using taxa suggested by Bolin (1936, 1944) and Yabe (1985) to be closely related. Additionally, this study hypothesized the intrarelationships of the genus using variation in skeletal and soft-tissue morphology. (Session 18, Sunday, July 8, Penn Stater, Room 208, 9:45)

SNOEKS, JOS
Leuvensesteenweg 13, Africa Museum, Tervuren, Tervuren B-3080 Belgium
The phylogeny of the East African cichlids: a morphologist's view
A decade ago, with the development of new techniques and the investment of considerable time and money, molecular studies started to produce alternative phylogenies of the East African cichlids that were repeatedly in conflict with existing trees. These latter trees were often based on overall resemblance rather than on a thorough morphology-based phylogenetic study. At present, conflicts are found on various taxonomic levels, from the presence of unexpected sisterspecies to the need to incorporate a morphologically completely different group to render a supposedly monophyletic group really monophyletic. While some conflicts have been solved using new morphological evidence that confirmed molecular results, other conflicts remain unresolved. Often, the presence of morphological convergence has been forwarded as a catch-all hypothesis to explain the differences. After a first wave of brake throughs by a few key players using a limited number of techniques, a second molecular wave recently emanated in which new researchers join in and apply various other techniques. Hence differences between the results of various molecular approaches now become apparent. Unravelling the reasons for the differences between the results of various approaches (morphological, molecular, and other) will undoubtedly become one of the important challenges of the next decade of phylogenetic research on African cichlids. (Session 6, Saturday, July 7, Penn Stater, Pres I Hall)

*SPARGO, ABBEY L., KOHLER, NANCY, SKOMAL, GREG, GOODWIN, ROB
(ALS) 141B Kersey Rd, University of Rhode Island, Wakefield, RI 02879; (NK) NMFS Laboratory, National Marine Fisheries/NOAA, Narragansett, RI 02882; (GS, RG) DMF, MA Division of Marine Fisheries, Vineyard Haven, MA 02568
The physiological effects of angling on post-release survivorship in juvenile sandbar sharks (Carcharhinus plumbeus).
A post release survivorship study of juvenile sandbar sharks (Carcharhinus plumbeus) was conducted in Delaware Bay during 1999-2000. A total of 104 sharks were captured and sampled for changes in blood chemistry after exposure to exhaustive exercise. Of these, 24 sharks were angled in the field, sampled, tagged, and released. The remaining 80 sharks were transported to a holding tank, allowed to recover, and half were angled to exhaustion. To quantify recovery, these fish were sampled at 0,1.5, 3, 6, 10, 14 and 24 hours, then tagged and released. Blood was obtained by caudal venipuncture and analyzed immediately for blood gasses and glucose. Serum samples were sent to a commercial laboratory for the determination of blood metabolites, proteins, and electrolytes. Blood levels of lactate, PCO[-2], glucose, potassium, Ca, Mg, and CK were elevated during stress, while pH and HCO[-3,+-] levels declined. Most metabolites returned to normal within 6-10 hours. Moreover, 5 sharks were recaptured 0.03-12 months after release over the course of the study. These preliminary data indicate that sandbar sharks are able to physiologically recover after the exhaustive exercise associated with rod and reel angling and therefore, catch and release fishing may not severely
impact neonatal and juvenile sandbar sharks in important nursery areas. (Session 20, Sunday, July 8, Penn Stater, Room 207, 11:30)

SPARKS, JOHN S.
Division of Fishes, University of Michigan, Ann Arbor, MI 48109
A phylogenetic analysis of cichlid fishes (Teleostei: Cichlidae) using morphological and nucleotide characters, with emphasis on the Malagasy and South Asian genera.
Phylogenetic relationships of cichlid fishes are investigated using morphological and nucleotide characters. Emphasis is placed on resolving relationships among the endemic Madagascan and South Asian genera. Results indicate that the Malagasy-South Asian cichlids are monophyletic. Two robustly supported clades are recovered within this assemblage, Ptychochrominae, comprising Ptychochromis, Ptychochromoides, and Oxylapia, all endemic Malagasy genera, and Etroplinae, comprising Paretroplus from Madagascar and Etroplus endemic to India and Sri Lanka. The phylogeny presented is congruent with the process of gondwanan drift-vicariance, and biogeography of cichlid fishes will be discussed in this context. (Session 18, Sunday, July 8, Penn Stater, Room 208, 8:30)

*STAUFFER, JAY R., MCKAYE, KENNETH R., KONINGS, AD
(JRS) 02 Ferguson Building, The Pennsylvania State University, University Park, PA 16802; (KRM) 301 Braddock Road, University of Maryland System, Frostburg, MD 21532; (AK) 417 Valplano Dr., Cichlid Press, El Paso, TX 79912
Behavior: An Important Diagnostic Tool for Lake Malawi Cichlids
In the lakes of East Africa, fishes of the family Cichlidae have undergone an extraordinarily rapid and extensive radiation. Within Lake Malawi there are over 450 described species of fish, and there may be as many as 1500 species that inhabit the lake, all of which have arisen in the last 2 million years. We hypothesize that behavioral characters are especially useful in delimiting many closely related species. Furthermore , we think that the use of such behavioral characters might eventually aid in a cladistic analysis of Lake Malawi cichlids. Such an analysis has not yet been possible using only morphological characters. For example, we hypothesize that bower form is a central component to female mate choice and reproductive behavior of the shallow water sand-dwelling cichlids. Moreover, we believe that male courtship behavior can be used as a diagnostic character to distinguish particular groups. For example, all species in the genus Tramitichromis, court in a figure-8 pattern, while species in the closely related Lethrinops court in either a circle or S-shaped pattern. Furthermore, members of a certain species groups in the genus Copadichromis also have a rock as part of their bowers, while members of another species group spawn in the open water over sand, and another reproduces in the open water over boulders. (Session 2, Friday, July 6, Penn Stater, Room 105, 5:00)

STEINER, PASCALE A.
Feldbergstrasse 22, Basel, Switzerland, Basel, Basel 4057 Switzerland
The activity pattern of the two carcharhinid shark species bull shark, Carcharhinus leucas and blacktip shark, Carcharhinus limbatus, in the estuary of the Ten Thousand Islands, Florida
Ultrasonic telemetry was used to determine the movement pattern of juvenile bull sharks Carcharhinus leucas and blacktip sharks, Carcharhinus limbatus in the estuary of the Ten Thousand Islands. A total of 11 bull sharks and 17 blacktip sharks were tracked between 4 and 23 hours. The sharks were tracked manually using a small boat with a trawling engine. The study was conducted during May through October 1999 and 2000.
All bull sharks except one remained within 2000 meters of the capture cite and they never left the estuary while tracking. Bull sharks movement patterns did not appear to be effected by the tide. Blacktip sharks left the area with the outgoing tide to then return on almost the same path with the incoming tide. Blacktip sharks swam as far as 7000 meters away from the capture site and up to 3000 meters away from the shoreline.
Only one bull shark displayed no tendency towards a specific core area where all the others showed places with significantly higher occupation rates, especially during daytime. All except three blacktip sharks occupied core areas. There was no significant difference in the swimming speed of the two shark species. (Session 10, Saturday, July 7, Penn Stater, Room 207, 11:30)

STEPHENS, PATRICK R.
Section of Amphibians and Reptiles, University of Pittsburgh/ Carnegie Museum of Natural History, Pittsburgh, PA 15213
Phylogeny, ecological diversification, and community structure in emydid turtles
Phylogenetic methods offer powerful tools for understanding the processes that generate and constrain ecological diversity in communities and lineages. In this study, we reconstruct the phylogeny of emydid turtles and then use this phylogeny to explore the ecological diversification of the group and the impact of phylogenetic history on the structure of present day emydid communities. Phylogenetic analysis was based on data from osteology, external morphology, behavior, allozymes, and mtDNA sequences and included all 40 recognized species of emydid turtles. There is no strongly supported incongruence between phylogenies from mtDNA and non-molecular data sets, and simultaneous analysis yields a fully resolved tree for all emydid species that supports the monophyly of the previously recognized subfamilies and genera (except Trachemys). Phylogenetic history has had a strong influence on emydid community structure. Communities in southeastern North America tend to have more aquatic species and fewer omnivores than communities in northeastern North American, which reflects phylogenetic trends in the ecology and the biogeography of the two basal emydid lineages. The ecological structure of emydid communities is the result of a variety of processes which can only be disentangled by incorporating phylogenetic approach (Session 35, Tuesday, July 10, Penn Stater, Room 108, 11:00)

*STEPIEN, CAROL A., DILLON, ALISON K.
(CAS) 1899 East 22nd St., Cleveland State University, Cleveland, OH 44114; (AKD) 3201 Carnegie Ave., Athersys, Inc., Cleveland, OH 44115
Genetic and Phylogeographic Relationships of the Invasive Round and Tubenose Gobies in the Great Lakes Versus Eurasian Populations
Population genetic and systematic relationships were investigated for two exotic fishes introduced to the Great Lakes in 1990, the round goby Neogobius melanostomus and the tubenose goby Proterorhinus marmoratus (Gobiidae: Neogobinnae), using mitochondrial DNA control region sequences. Round gobies were analyzed from sites in the Great Lakes, an introduced population from the Gulf of Gdansk in Poland, and a native population from the northern Black Sea. The round goby had relatively high genetic variability, and 17 haplotypes were identified from 64 individuals. Levels of genetic variation for the round goby were similar in the invasive and native sites, suggesting relatively large founding populations and lack of bottlenecks. The northern Black Sea was eliminated as a founding source for the Great Lakes and the Gulf of Gdansk. Significant differences occurred among the Great Lakes and Eurasian samples, and between Lakes Erie and St. Clair. No variation was detected in the tubenose goby population in the Great Lakes, which has been less successful. A molecular clock calibration suggests the genera Neogobius and Proterorhinus diverged about 5.2 ± 1.0 million years ago, apparently separating from a common ancestor shared with Gobius during the isolation of the Paratethys basin from the Mediterranean Tethys Sea. (Session P-24, Sunday, July 8, Penn Stater, Deans Hall)

*STEPIEN, CAROL A., DILLON, ALISON K.
(CAS) 1899 East 22nd St., Cleveland State University, Cleveland, OH 44114; (AKD) 3201 Carnegie Ave., Athersys, Inc., Cleveland, OH 44115
Phylogeography of the ruffe Gymnocephalus cernuus: glacial refugia, the leading edge hypothesis, and exotic introductions
Phylogeographic relationships among seven European populations of the ruffe Gymnocephalus cernuus (Percidae: Teleostei) were analyzed in comparison with two invasive population sites in the North American Great Lakes using mitochondrial control region and nuclear intron DNA sequences. The ruffe colonized Lake Superior in about 1986 via ballast water discharge, and was accidentally transported in 1995 to Lake Huron. It it now one of the most common nearshore fishes in western Lake Superior and feeds on eggs and young of native fishes. Five mtDNA haplotypes were discerned from sequencing the entire 1024 base pair control region for 126 specimens. The haplotypes were distributed across the native range of G. cernuus, and all but one of the sampling locations contained a single type. Low genetic variability also was revealed from the LdhA6 intron sequences (totaling 273 bp). Genetic divergence patterns among the mtDNA haplotypes showed two primary groups in western and eastern Europe. Low genetic variability in both mitochondrial and nuclear DNA sequences is attributed to population bottlenecks in glacial refugia and founder events during post-Pleistocene recolonization. The North American invasion appears to have originated from the Elbe River drainage region in northwestern Europe, based on matched nuclear and mitochondrial DNA sequences. (Session 38, Tuesday, July 10, Penn Stater, Room 207, 2:15)

*STIASSNY, MELANIE L. J., SPARKS, JOHN S.
(MLJS) Central Park West at 79th Street, American Museum of Natural History, New York, NY 10024; (JSS) Division of Fishes, University of Michigan, Ann Arbor, MI 48109
Origins, relationships, and biogeography of Madagascar's freshwater fishes
For students of gondwanan biogeography the origin(s) and composition of Madagascar's extant freshwater fish fauna remains a mystery. Missing in both the contemporary and fossil record are several major groups of freshwater fishes found in Africa, Africa-India, and Africa-South America-India-Southeast Asia. Moreover, representatives of Madagascar's extant freshwater fish groups are absent from Cretaceous deposits on the island. This lack of fossil evidence has led paleontologists to conclude that the island's extant freshwater fish fauna is descended from post-Mesozoic (marine) colonizers, and not from freshwater taxa isolated on Madagascar by the fragmentation of Gondwana. Despite a lack of fossil corroboration, our current understanding of the phylogenetic relationships of many freshwater fish clades with members present on Madagascar (Cichlidae, Aplocheiliidae, Pellonuline Clupeidae, Bedotiidae) present a compelling argument in support of drift-vicariance. Despite the problems inherent with this interpretation, it seems improbable that these congruent distributional patterns could have resulted from repeated independent intercontinental marine dispersals. Finally, we present evidence from recent island-wide surveys to counter the claim that Madagascar is characterized by a notably depauperate freshwater ichthyofauna. (Session 39, Tuesday, July 10, Penn Stater, Room 206, 1:45)

*STONER, DOUGLAS S., ANDERSON, CHRISTOPHER, HOPPMANN, EMILY, QUATTRO, JOSEPH M.
400 Sumter, University of South Carolina, Columbia, SC 29208
Phylogeography and conservation genetics of an endangered marine fish, the barndoor skate, Dipturus laevis
Analyses of long-term research surveys on the continental shelf between the Grand Banks of Newfoundland and southern New England suggest that the barndoor skate is at risk of extinction. This flattened, bottom-dwelling fish, which can grow up to 5 feet long, was one of the more abundant fish in the Northwest Atlantic as recently as the 1950s. But since then, heavy fishing pressures reduced the numbers of barndoor skates so precipitously that it is now the subject of a petition for listing under the U. S. Endangered Species Act. To help in the development of a management strategy to preserve the barndoor skate, we undertook a survey that consisted of the genetic typing of individual barndoor skates using mitochondrial markers. The sites where these individuals were collected were selected such that they would span a large portion of the barndoor skates' geographic range. Statistical analysis of the data generated by this survey provided estimates of genetic diversity, degree of population subdivision, effective population size, and evolutionary relationship among sampled populations. The implication of these statistical findings are discussed with respect to the future management of barndoor skate populations, particularly regarding maintenance of genetic variation, reintroduction strategies, site selection of marine preserves, and the setting of future conservation priorities. (Session 38, Tuesday, July 10, Penn Stater, Room 207, 2:30)

*STRANGE, REX M., LOUDERBACK, VALERIE
Southeast Missouri State University, Cape Girardeau,, MO 63701
Male reproductive investment in Catonotus darters
Female selectivity in mate choice is a primary focus in reproductive ecology because females typically make a greater reproductive investment than males. However, sometimes males may make a substantial investment in reproduction. Catonotus darters practice a form of resource-defense polygyny in which males establish and guard a nest under rocks or other solid submergent debris. Nest guarding may last approximately two to three weeks, during which time the male's ability to forage is reduced to the area around his nest. We examined the possibility of reduced feeding in nest-guarding males in three species (Etheostoma crossopterum, E. oophylax, and E. smithi) by comparing the food habits of males and females before, during, and after the spawning season. The dietary differences between species may be attributable to the relative sizes of the three species. Etheostoma smithi is the smallest species in our study (mean male SL = 37.6 mm) and preys on dipteran larvae throughout the year. However, the diets of males and females differ in E. smithi during spawning seasons: the mean number of prey items per male examined averaged three (range 0-5) during this time, whereas females had consumed approximately 15-20 items before capture. Etheostoma crossopterum (mean male SL = 62.7 mm) and E. oophylax (mean male SL = 50.63 mm) are larger species and prey heavily on various invertebrates outside the spawning season, including dipteran and trichopteran larvae, and amphipod and isopod crustaceans. We observed qualitative and quantitative shifts in the diet of E. crossopterum and E. oophylax males and females during the spawning season. Breeding females predominately consumed dipteran and trichopteran larvae, with an average of 13-15 individual prey items per stomach examined. Male diets shifted to isopod and amphipod crustaceans during the breeding season, with an average of seven items per stomach. We note that the males of E. crossopterum and E. oophylax shift toward larger, more cursorial prey organisms during spawning. Isopod and amphipod crustaceans may be too large for E. smithi males, restricting the available food items to those found immediately around the nest site. Given that a larger size may act as a metabolic buffer in larger fishes, we expect that larger males are able to guard nests for a longer duration than smaller males. If so, we predict that any attribute (behavior or morphology) that allows a smaller male to establish a nest quickly is selectively advantageous. (Session P-32, Monday, July 9, Penn Stater, Deans Hall)

*STRANGE, REX M., MAYDEN, RICHARD L.
(RMS) Department of Biology, Southeast Missouri State Univesity, Cape Girardeau, MO 63701; (RLM) Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487
Phylogenetic relationships among North American Phoxinus species (Teleostei: Cyprinidae) as inferred from mitochondrial cytochrome b sequences: Taxonomic and Biogeographic considerations.
We estimated phylogenetic relationships among species currently placed in the genus Phoxinus and representatives of other cyprinid clades using cytochrome b sequence variation. Our analyses resolved five monophyletic groups: 1) shiner clade, 2) tribe Abramini, 3) western clade, 4) subgenus Chrosomus (inclusive of all North American Phoxinus), and 5) European Phoxinus. Relationships among these clades are essentially unresolved, and Phoxinus species from Europe and North America do not form a monophyletic group. Among North American Phoxinus species the subgenus Chrosomus is sister to the monotypic subgenus Pfrille (P. neogaeus). Chrosomus consists of two monophyletic groups. Phoxinus erythrogaster and P. eos form the 'P. erythrogaster clade' that is sister to the 'mountain dace clade' containing two sister-species pairs. Phoxinus cumberlandensis and the undescribed laural dace form one species pair that is sister to P. oreas plus P. tennesseensis. These findings are consistent with known biogeographic and geological histories of the areas and apparent adaptive trends involving reproductive behavior among North American Phoxinus. Research was supported in part by the National Science Foundation (DEB 9307132) and The University of Alabama. (Session 23, Sunday, July 8, Penn Stater, Room 208, 1:30)

STRECKER, ULRIKE
Martin-Luther-King-Platz 3, University of Hamburg, Hamburg D-20146 Germany
Genetical and Behavioral Aspects of Speciation in the Endemic Cyprinodon Species of Laguna Chichancanab, Mexico
In Laguna Chichancanab a species flock consisting of five species has evolved. Behavioral studies on three species show that different mating preferences exist indicating different stages of isolation: complete in C. maya, indiscriminate in C. beltrani and intermediate in C. labiosus. These results are consistent with mtDNA data showing that the species have a high level of haplotype frequency overlap. Only for C. maya no overlap exists. I performed a preliminary analysis of five microsatellite loci in the species flock and their geoprahically isolated sister species C. artifron. The Fst values between C. artifrons and C. maya versus the members of the flock indicate no gene flow. Between the other species a potential of gene flow exists which is even stronger between C. beltrani and C. verecundus. Phylogenetic relationship shows three clusters: C. artifrons, C. verecundus with C. beltrani and C. maya, C. simus with C. labiosus. The grouping might result from different dates of origins and/or divergent evolutionary rates. All results support the idea that achieved levels of reproductive isolation vary in the species flock. Only C. maya is reproductively isolated, all other species still show introgression but at different levels. (Session 33, Tuesday, July 10, Penn Stater, Pres I Hall)

STURMBAUER, CHRISTIAN
Technikerstr. 25, University of Innsbruck, Innsbruck, Tirol A-6020 Austria
Alternative Patterns of Eco-morphological Diversification and Speciation in Lake Tanganyika Cichlid Fishes
East African lakes provide excellent model systems to study evolutionary processes leading to speciation and eco-morphological diversification. By means of molecular data it is possible to address the timing and succession of major cladogenesis events and to delineate the pathways of eco-morphological diversification. The evolutionary analysis of the Lake Tanganyika cichlid radiation suggests that all habitat types and niches therein were aleady occupied shortly after the formation of a lacustrine environment. Further eco morphological diversification was mostly achieved within the lineages via niche segregation leading to a more finescale differentiation among new species. Lake level fluctuations had a massive impact on diversification events during advanced stages of the radiation. A rapid rise of the lake level synchronized the onset of geographic and genetic isolation among several founder populations of rock cichlids, so that all species which originated from this event exhibit equal genetic distances to each other. Parallel evolution of corresponding eco-morphological specialization seems to be particularly likely under these circumstances. This is shown on the example of the Tropheini. Lake level fluctuations may sometimes cause hybridization among previously isolated evolutionary entities. The possibility for the origin of a new species through hybridization is documented for the lamprologine cichlid Neolamprologus marunguensis. (Session 15, Sunday, July 8, Penn Stater, Pres I Hall)

*SULLIVAN, JOHN P., LAVOUÉ, SÉBASTIEN, ARNEGARD, MATTHEW E., TEUGELS, GUY, HOPKINS, CARL D.
(JPS) Dept. Ichthyology, Cornell University, New York, NY- 10024; (SL) Laboratoire d'Ichtyologie Générale et Appliquée, Cornell University, Paris, - 75005 France; (MEA, CDH) 263 Mudd Hall, Cornell University, Ithaca, NY- 14853; (GT) Koninklijk Museum voor Midden-Afrika /, Musée Royal de l'Afrique Centrale, Tervuren, - B-3080 Belgium
Discovery of a riverine species flock of African electric fishes (Mormyridae, Teleostei)
We have discovered a clade of mormyrid electric fish from Gabon, Africa with 38 unique forms based on morphology and electric organ discharges (EODs), but only four correspond to described species. The remainder, treated here as operational taxonomic units (OTUs), may be new.
After sequencing the cytochrome-b gene from 86 specimens and recovering 65 distinct cyt-b haplotypes, we obtained trees both by maximum parsimony and maximum likelihood, using outgroup sequence data to root the tree. There is strong support for the monophyly of all 38 OTUs and the small genetic distances between distinct forms suggests an ongoing and rapid radiation. For some, the cytochrome b tree topology fails to support the monophyly of individual OTUs, or close relationships between OTUs which are similar in morphology and EOD characteristics. In others, individuals from distinct OTUs share identi cal, or similar, haplotypes. The presence of divergent haplotypes within a single population suggests incomplete lineage sorting; grouping of phenotypically distinct, geographically proximate forms suggests local hybridization and introgression of mitochondrial genomes among forms. Both may contribute to the difference between the gene tree and the natural groups. We find many parallels between these riverine electric fishes and the well-known lacustrine fish "species flocks." (Session 2, Friday, July 6, Penn Stater, Room 105, 4:30)

*SUMMERS, ADAM P., HERNANDEZ, L. PATRICIA
(APS) 321 Steinhaus Hall, UC Irvine, Irvine, CA 92697; (LH) Department of Biology, Wesleyan University, Middletown, CT 06459
Why are cartilaginous fishes so big?
The largest fishes in the sea have cartilaginous skeletons. There are a number of hypotheses as to why this might be true, though none explain the diversity and number of very large cartilaginous fishes. There is a functional limitation on size that may be a general explanation for the skewed size distribution. As a fish grows, its weight and the negative buoyancy of its skeleton grows as the third power of length. At the same time the thrust and lift generated by the fins grow with the square of length. At some length, there will be insufficient lift to counter the sinking force of the skeleton. A cartilaginous skeleton weighs less than a bony skeleton of the same length, so this theoretical maximal size is larger for the cartilaginous fish. This may provide an explanation for why the eight largest fishes are cartilaginous and the two largest bony fishes have cartilaginous skeletons. We show that cartilaginous fishes do have lighter skeletons per unit length than do bony fishes and that the heaviest cartilaginous skeletons are from benthic fishes. (Session 29, Monday, July 9, Penn Stater, Room 105, 8:00)

*SUMMERS, ADAM P., KETCHAM, RICHARD, ROWE, TIMOTHY
(APS) 321 Steinhaus, UC Irvine, Irvine, CA 92697; (RK, TR) CT scan Facility, UT Austin, Austin, TX 78712
The ontogeny of the hornshark chndrocranium and the evolution of trabecular cartilage.
The skeleton of the chondrichthian fishes is composed of cartilage, some of which is calcified. The vertebrae are completely calcified, while the remainder of the skeleton has one or more thin layers of calcified blocks covering a core of uncalcified cartilage. In a clade of stingrays containing hard-prey specialists an internal network of calcified struts augments the surface calcification. This strut-reinforced tissue is called trabecular cartilage. Some sharks also eat hard prey. We examined a series of Heterodontus francisci with a high-resolution CT scanner for evidence of trabecular cartilage. The CT scans and dissection revealed no trace of trabeculae. The jaws are the mechanical antithesis of those of hard-prey crushing stingrays. Rays have a well-calcified symphysis and the jaws meet at a joint with a large uncalcified region. In contrast heterodontids have a loose, uncalcified, ligamentous symphysis and the jaw joint is a well calcified hinge. Dissection of other shark taxa that are reported to eat hard prey, Sphyrna tiburo and Orectolobus ornatus, did not reveal any trabecular cartilage. Trabecular cartilage appears to be an evolutionary innovation, confined to the myliobatid stingrays that allows them to eat harder prey than other cartilaginous fishes. (Session P-14, Saturday, July 7, Penn Stater, Deans Hall)

*SWANSON, BROOK O., GIBB, ALICE C., MARKS, JANE C., HENDRICKSON, DEAN A.
(BOS) Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86001; (ACG) Northern Arizona University, Flagstaff, AZ 86001; (JCM) Box 5640, Northern Arizona University, Flagstaff, AZ 86011; (DAH) Texas Natural History Collections, University of Texas at Austin, Austin, TX 78712
Feeding behavior repertoire of the polymorphic cichlid, Cichlasoma minckleyi
Previous research has described the repertoire of feeding behaviors for African cichlids. The wide range of behaviors observed within a species has been hypothesized to contribute to the broad trophic success of cichlids, and to their adaptive radiations within African lakes. It is not known if New World cichlids share this plasticity in feeding behavior. In this study we examined the feeding behavior of a Mexican cichlid, Cichlasoma minckleyi, in the field. This species shows two distinct morphotypes. One morphotype has robust musculature and large, flattened, molariform teeth on the pharyngeal jaws. The second morphotype has gracile jaws with needle-like, papilliform teeth. Individuals were caught, anesthetized, and labeled with numbered tags. Tagged fish were observed in the water and feeding behaviors were recorded using digital video. Feeding sequences were analyzed in the lab and behaviors were identified, categorized and compared to published descriptions of African cichlid feeding behaviors. Preliminary analysis of our data suggests that C. Minckleyi utilizes at least seven of the eight behaviors described for African cichlids. These results suggest that the behaviors have been conserved among divergent cichlid groups. Quantitative comparisons of the two morphotypes will determine if there are differences in feeding behaviors. (Session 11, Saturday, July 7, Penn Stater, Room 206, 11:30)

SWITZER, JOHN F.
Saint Louis University, St. Louis, MO 63103
Cytochrome b sequence variation in the Arkansas Saddled Darter, Etheostoma euzonum (Actinopterygii: Percidae).
Etheostoma euzonum, is endemic to the White and Black river systems of Missouri and Arkansas. Hubbs and Black described E. euzonum as two subspecies. The nominate subspecies was described from the Buffalo River and considered to occur in the White River system above Batesville AR. E. euzonum erizonum was described from the Current River, the only river system in which it occurs. Individuals from the Spring and Strawberry rivers, which are located geographically between the White and Current river systems, were not assigned to either subspecies. Page and Cordes (1983) conducted a re-examination of morphological variation within E. euzonum and concluded that populations from the Strawberry and Spring rivers are intergrades of the two subspecies. A phylogenetic analysis of E. euzonum based upon complete cytochrome-b sequence data of 18 individuals from 7 populations was conducted to determine the extent of genetic variation between these two subspecies and relationships between drainage populations. All trees resolved individuals from the Current River as a monophyletic group sister to a clade composed of two monophyletic groups. One comprised of individuals from the Spring and Strawberry rivers and the other comprised of individuals from the upper White and the Little Red rivers. (Session 12, Saturday, July 7, Penn Stater, Room 208, 1:45)

TABORSKY, MICHAEL
Institute of Zoology, University of Bern, Hinterkappelen/Bern CH-3032 Switzerland
Cichlids as a paradigm for social evolution in vertebrates
Among vertebrates, lamprologine cichlids from Lake Tanganyika exhibit some of the most highly developed social systems known to date. In contrast, most haplochromine cichlids from Lake Malawi and Lake Victoria show very simple levels of social organization. The clue to this difference is the mode of brood care. While mouthbrooding most often involves uniparental care and a short contact between the sexes only for mating, the benefit to substrate brooders of joint brood care may cause long-term pair bonds and the development of a family structure. In some species, the young remain in their natal territories and help in all duties of territory maintenance, defence and brood care, and they may participate in reproduction. Our study of Neolamprologus pulcher revealed a considerable reproductive conflict mainly between male family members. The allocation of energy to behaviour, growth, reproduction and storage differs between family members according to status, maturity and sex as expected from the divergent options of these fish. I shall discuss how the reproductive pattern and ecology of this species may select for advanced levels of sociality, which may be regarded as a paradigm for mechanisms of social evolution in vertebrates. (Session 15, Sunday, July 8, Penn Stater, Pres I Hall)

TAKAHASHI, TETSUMI
Lake Biwa Mseum, Shiga prefecture, Japan Science and Technology Corporation, Kusatsu, Shiga 525-0001 Japan
Evolution of the cichlid fishes in Lake Tanganyika
Lake Tanganyika, located in the African Rift Valley, is one of the largest and deepest freshwater lakes in the world. The ichthyofauna of this lake is characterized by the extremely high endemism and the numerical dominance of the Cichlidae, with about 60 genera and 200 species. Several molecular studies have examined phylogenetic relations among various of these fishes, but a phylogenetic analysis covering all 12 tribes and using morphological data has yet to be made. The present study was undertaken in order to develop a hypothesis on the phylogeny of the Tanganyikan cichlid fishes based on certain internal and external morphological features.
All of the 49 genera that are endemic to Lake Tanganyika and nine non-endemic genera, covering all 12 tribes of the Tanganyikan cichlids, were examined. Phylogenetic relationships were cladistically estimated by using the maximum parsimony method.
The resulting morphological tree confirmed the monophyly of six of these tribes. However, when this tree was compared with molecular trees that had been proposed previously, the branching order among tribes differed. It is believed that these differences are probably the result of some as yet unclarified convergent evolution. (Session 6, Saturday, July 7, Penn Stater, Pres I Hall)

TANG, KEVIN L.
Natural History Museum and Biodiversity Research Center, The University of Kansas, Lawrence, KS 66045
A phylogenetic analysis of the family Pomacentridae (Teleostei:Perciformes) using morphological data.
The phylogenetic relationships within the Pomacentridae are largely unresolved. The purpose of this study is to obtain a hypothesis of the relationships among the pomacentrid genera and subfamilies using morphological evidence, then combining this data with molecular data to produce a hypothesis based on total evidence. Species from all four recognized subfamilies were included in this study. Representatives from 15 pomacentrid genera (Abudefduf, Amblyglyphidodon, Amphiprion, Chromis, Dascyllus, Hypsypops, Lepidozygus, Mecaenichthys, Microspathodon, Neoglyphidodon, Parma, Plectroglyphidodon, Pomacentrus, Premnas, and Stegastes) were examined. Representatives from three families (Cichlidae, Embiotocidae, and Labridae) were included as outgroup taxa. Twenty-four ingroup taxa and three outgroup taxa were examined. The majority of characters are osteological. A phylogenetic analysis of these data found support for the monophyly of well-established groups like the Pomacentridae and Amphiprioninae. The results of the morphological anaylsis will be discussed in relation to a previously proposed molecular hypothesis. Both data sets converged on the same result in many cases. The results of a total evidence analysis will be presented. (Session 18, Sunday, July 8, Penn Stater, Room 208, 11:00)

*TAYLOR, CHRISTOPHER M., WILLIAMS, LANCE R., FIORILLO, RICCARDO A., THOMAS, R. B., WARREN, JR., MELVIN L.
(CMT) P.O. Drawer GY, Mississippi State University, Mississippi State, MS 39762; (LRW) Box 552, Louisiana College, Pineville, MS 71359; (RAF) 315 Shorter Ave., Shorter College, Rome, GA 30165; (RBT) 800 University Way, Univ. of S. Carolina Spartanburg, Spartanburg, SC 29303; (MLW) 1000 Front Street, USDA Forest Service, Oxford, MS 38655
Fish Assemblage structure and stability under variable environmental conditions in the Ouachita Mountains.
We tested the general hypothesis that fish assemblage variability in space and time could be explained by gradients in stream size and flow variability. Fishes and habitat were sampled quarterly for three years at 12 sites (144 samples) in the upper Saline and Ouachita River drainages, Arkansas. Detrended and Canonical Correspondence analyses were used to describe assemblage structure in space and time. Across all sites and samples, assemblage variability was significantly associated with a stream size/flow variability gradient. Assemblage stability (defined by sample spread in DCA space) also was strongly associated with this environmental gradient. Ecological theory suggests that "diversity begets stability". For our data, local species richness was strongly associated with assemblage stability. The question remains, which has the most important influence on assemblage stability, the environment or the local diversity of the fauna? We suggest that the assemblage patterns are largely driven by environmental variation and will discuss our reasoning. (Session 8, Saturday, July 7, Penn Stater, Room 206, 8:45)

*TAYLOR, MARTIN I., VERHEYEN, ERIK, RUBER, LUKAS
(MIT) University of East Anglia, Norwich, Norfolk NR4 7TJ UK; (EV) Section Taxonomy and Biochemical Systematics, Royal Belgian Institute of Naural Sciences, Brussels, Flanders 1000 Belgium; (LR) Jose Gutiérrez Abascal 2, Museo Nacional de Ciencias Naturales, Madrid, - 28006 Spain
Microsatellites reveal high levels of population substructuring in the species-poor, Eretmodine cichlid lineage from Lake Tanganyika.
We investigated fine scale population substructuring in an apparently monogamous, biparental mouthbrooding cichlid. Microsatellite allele frequencies were determined at four polymorphic loci for nine populations of Eretmodus cyanostictus. We provide empirical support for the hypothesis that a species employing this breeding strategy should exhibit high levels of population substructuring. Stretches of sand represent considerable barriers to dispersal, and in contrast to the mbuna of Lake Malawi, distance alone, along a continuous rocky shoreline is sufficient to significantly reduce gene flow. There was a significant pattern of isolation by distance along both the whole study area, and over the stretch of continuous shoreline, suggesting that this species has poor dispersal capabilities, and that juveniles establish territories close to their natal site. Despite limited dispersal, E. cyanostictus populations were not significantly more inbred than a more widely dispersing rock-dwelling cichlid from Lake Malawi. This finding may cast doubt on the hypothesis that polyandry has evolved as a mechanism to maintain genetic diversity in Lake Malawi cichlids. High levels of substructuring may not always promote high levels of speciation, and other factors such as the intensity of sexual selection may be a more important factor in determining the speciation potential of a lineage. (Session 15, Sunday, July 8, Penn Stater, Pres I Hall)

TAYLOR, MICHAEL S.
202 Life Sciences Bldg, Louisiana State University, Baton Rouge, LA 70803
Systematic relationships of the Neotropical goby genus Elacatinus (Gobiidae: Gobiosomini)
Although Elacatinus is the largest genus of Neotropical gobies, the systematic relationships within the genus remain largely unknown. Two subgenera, Elacatinus and Tigrigobius, are recognized within the genus. Bóhlke and Robins (1968) divided the subgenus Elacatinus into two morphological groups, and Colin (1975) followed with a tenative dendrogram of relationships for the subgenus. Van Tassell (1998) proposed elevation of Tigrigobius to generic status, despite being paraphyletic with respect to Elacatinus. To provide additional insight into the intrageneric relationships, I sequenced 1140 bp of the mitochondrial cytochrome b gene. Maximum likelihood analyses reveals a monophyletic clade comprised of the Atlantic members of the subgenus Elacatinus. Within this Atlantic clade are two well-supported subclades representing cleaning and sponge-dwelling behaviors. Tigrigobius is comprised of two monophyletic clades. The first clade is sister to the Atlantic Elacatinus and contains most Atlantic Tigrigobius, plus E. puncticulatus in the Pacific. The latter species was previously assigned to Elacatinus but a Tigrigobius alignment is supported. The second Tigrigobius clade is sister to the previous two clades and is comprised of the remaining Pacific Tigrigobius, plus E. multifasciatus and Ginsburgellus novemlineatus in the Atlantic. (Session 35, Tuesday, July 10, Penn Stater, Room 108, 9:00)

TAYLOR, MICHAEL S.
202 Life Sciences Bldg, Louisiana State University, Baton Rouge, LA 70803
Population structure in a widely distributed Neotropical goby, Elacatinus evelynae
Most marine organisms are thought to have panmictic populations due to long distance dispersal of their pelagic larvae. Few studies of Caribbean fishes have found evidence of genetic population structure and none have examined such structure in a phylogeographic context. Elacatinus evelynae, found throughout the Bahamas and Caribbean Sea, has an approximately 20-25 day planktonic larval phase. Preliminary analyses of 400 bp from cytochrome b from populations from Cura´cao, Barbados, St. Croix, Navassa, and Exuma Sound in the Bahamas revealed strong phylogeographic structure with no haplotypes shared among populations. Overlaid on this geographic structure are three allopatrically distributed color forms of E. evelynae. The yellow form is approximately 3.5% diverged from blue and white forms, while genetic differences between the latter two forms is closer to 1%. Whether apparent genetic differences among color forms is due entirely to geography or also reflects selection due to coloration remains to be resolved and potential genetic mechanisms will be discussed. (Session 12, Saturday, July 7, Penn Stater, Room 208, 2:15)

*TERAI, YOHEY, OKADA, NORIHIRO
4259 Nagatsuta-cho, Tokyo Institute of Technology, Yokohama 226-8501 Japan
The complexity of alternative splicing of the hagoromo gene increases in explosively speciated lineage in East African cichlid fishes
Mate choice, based on coloration, might be one cause of speciation that led to the explosive adaptive radiation of cichlid fishes in the lakes of East Africa. We isolated the cichlid homologue of the hagoromo (hag) gene of zebrafish that was cloned from a stripe-pattern mutant. We detected nine different types of hag mRNA in cichlids that were products of alternative splicing. Cichlids in an explosively speciated lineage expressed a greater variety of hag transcripts, produced by alternative splicing, than those in an old lineage, suggesting that species in the explosively speciated lineage have acquired complex splicing mechanisms within such a very short evolutionary period. (Session 15, Sunday, July 8, Penn Stater, Pres I Hall)

*TERWILLIGER, MARK R., MURTAUGH, PAUL A., KANN, JACOB, MARKLE, DOUGLAS F.
(MRT, DFM) 104 Nash Hall, Oregon State University, Corvallis, OR 97331; (PAM) 66 Kidder Hall, Oregon State University, Corvallis, OR 97331; (JK) 232 Nutley St., Aquatic Ecosystem Sciences, LLC., Ashland, OR 97520
Associations between water quality and daily growth of juvenile shortnose suckers (Chasmistes brevirostris) and Lost River suckers (Deltistes luxatus) in Upper Klamath Lake, Oregon
Otolith increment widths were used as a surrogate for juvenile daily growth rate of two species of endangered suckers in hypereutrophic Upper Klamath Lake. Residuals from an ontogenetic baseline were analyzed in a linear mixed effects model using data from 232 shortnose suckers (Chasmistes brevirostris), 120 Lost River suckers (Deltistes luxatus), and average lakewide values for daytime water temperature and pH and nighttime dissolved oxygen. As expected, temperature was usually positively associated with growth. However, contrary to expectations, pH was positively associated and nighttime dissolved oxygen negatively associated with growth in most models. In addition, examination of growth associated with lethal levels of un-ionized ammonia failed to show an effect. Local conditions in some parts of Upper Klamath Lake are such that juvenile suckers should experience mortality or sublethal growth effects. However, the processes that lead to those conditions are also associated with increased food production. Our methodology may have detected those conditions associated with good food production and growth, and may have failed to detect sublethal effects of poor water quality on growth. We hypothesize that individuals surviving these conditions either experienced brief exposure or found local refugia from poor water quality. (Session 22, Sunday, July 8, Penn Stater, Room 206, 2:45)

THOMAS, K. REBECCA
Field Museum (FISHES), University of Chicago, Chicago, IL 60605
Developmental timing, ossification and morphometric variation in the zebrafish, Danio rerio
Events occurring later in ontogeny are often thought to be more variable than events occurring earlier in ontogeny; however, few studies have considered how developmental timing relates to morphometric variation. Using Danio rerio, this study tested the hypothesis that early ossifying bones exhibit less variation in size and shape than bones ossifying relatively later in ontogeny. Approximately 50 adult D. rerio were cleared & stained for bone with alizarin red. Relatively early and late ossifying bones of similar size and shape were identified for comparison based on previous studies that determined the sequence of ossification for bones in the skull, pectoral, and pelvic girdles of D. rerio. Each bone was digitally imaged, and its outline was digitized with equally spaced points. Measures of size and shape were derived from GLS superimposition of these digitized outlines. Variability in size and shape of early and late ossifying bones was then compared using nonparametric bootstrapping to test for significance. (Session 29, Monday, July 9, Penn Stater, Room 105, 11:00)

*THOMAS, MATTHEW R., GRADY, JAMES M.
(MRT) Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901; (JMG) Department of Biological Sciences, University of New Orleans, New Orleans, LA 70148
Intraspecific variation in Noturus stigmosus and differentiation from Noturus eleutherus (Siluriformes: Ictaluridae), based on morphology and mitochondrial DNA
Patterns of geographic variation in morphology suggest that the northern madtom, Noturus stigmosus, is polytypic. Multivariate analysis of morphometric data and comparisons of pigmentation patterns indicated divergent morphotypes between tributaries of the Mississippi River in western Tennessee and Mississippi and Ohio River drainages. Specimens from Mississippi R. tributaries have longer pectoral and dorsal spines, shorter adipose fin, and shorter anal fin base. In the Ohio River drainage, N. stigmosus is morphologically similar to and sympatric with the mountain madtom, Noturus eleutherus, with which it is often confused. Analyses of morphometric and meristic data revealed consistent separation of both species throughout the Ohio River drainage. Noturus stigmosus differs from N. eleutherus in having longer pectoral and dorsal spines, shorter adipose fin, and longer first dorsal saddle. Also, N. stigmosus has a higher modal number of caudal rays and preoperculomandibular pores. Preliminary analyses of mitochondrial cytochrome b (Cytb) variation support the morphological partition between N. eleutherus and N. stigmosus. Partial Cytb sequences (495 bp) for these taxa are 6% divergent. We are currently investigating patterns of mtDNA variation as a test of the morphological hypothesis that N. stigmosusrepresents two distinct taxa. (Session 12, Saturday, July 7, Penn Stater, Room 208, 11:00)

*THOMAS, MICHAEL L. L., STINSON, CHAD
9053 Route 148, US Fish and Wildlife Service, Marion, IL 62959
Herpetofauna of Crab Orchard National Wildlife Refuge
>From July of 1999 through September of 2001, a presence absence study was conducted by the Carterville Fishery Resource Office. The study was to determine the distribution of amphibians and reptiles within the Crab Orchard National Wildlife Refuge (CONWR) which is located in Williamson County in southern Illinois. The survey was initiated to enhance the existing species list for the refuge, using sampling methods that included song surveys, drift fences, and search and seizers. Song surveys were performed at night; recordings were made in the field and vocalization identifications were made in the lab. Drift fences were constructed and four study sites were selected for monitoring. Fences were checked 2-3 times weekly and organisms were returned to the lab for identification. Drift fence habitats included a wooded hillside, wooded lowlands, wooded area near a creek and a grassland pasture near a ephemeral pond. Search / seizers were performed by driving on roads frequently during or after warm rains and by visual encounter surveys. Seizers also included the collection of amphibian egg masses from 13 sites. The study resulted in a species list of 28 reptiles and 20 amphibians on CONWR (Session P-32, Monday, July 9, Penn Stater, Deans Hall)

THOMPSON, BRUCE A.
Wetland Resources Bldg, Louisiana State University, Baton Rouge, LA 70803
Distribution, life history, systematics, and conservation status of Fundulus jenkinsi, the saltmarsh topminnow
Fundulus jenkinsi is endemic to the Gulf coast of southern United States, ranging from Galveston Bay, Texas, eastward through Louisiana, Mississippi, Alabama, into the western panhandle of Florida in Escambia Bay. All records are in the shallow part of the Gulf of Mexico or margins of estuaries. Very little habitat or life history information has been published. Body patterns and spawning colors have been lacking, resulting in many misidentification and erroneous museum records. Recent captures during the height of spawning season shows that male jenkinsi develop bright lemon yellow and russett orange in their anal and dorsal fins. Males also develop contact organs on the anal fin and lateral body scales. There has been little agreement on the phylogenetic relationship of jenkinsi, having been aligned with several species. F. jenkinsi is presently a Federal candidate species, but recent sampling shows it to be more abundant than literature or museum records might suggest. (Session 38, Tuesday, July 10, Penn Stater, Room 207, 1:45)

THOMPSON, KENNETH W.
Dept. Biological Sciences, Lock Haven University of Pennsylvania, Lock Haven, PA 17745
Adaptation of digital technology to classroom cytotaxonomic studies using karyotypes of the butterfish, Peprilus triacanthus (Perciformes, Stromateidae).
Ten specimens of P. Triacanthus were collected during July 2000 near Wallops Island, Virginia. Collections were made inshore by seining and offshore by trawling. Air-dried C-metaphase slides were prepared and preliminary analyses carried out as an ichthyology class project during the 2000 summer sessions at the Wallops Island Marine Science Consortium campus. A chromosome formula of 48/48 was determined for this species. The replacement of conventional photography with digital techniques allowed the project to be completed in less than one week. This relatively short time period and hands on processing maintained higher student interest than has been the case when using conventional techniques relying on lengthy darkroom procedures. (Session 39, Tuesday, July 10, Penn Stater, Room 206, 2:30)

TRAPANI, JOSH
1109 Geddes Road, University of Michigan, Ann Arbor, MI 48109
The cichlids of Cuatro Cienegas, Mexico: number of morphs and genetic and environmental contributions to trophic morphology
The cichlids of the Cuatro Cienegas Basin (Coahuila, Mexico) have been extensively studied and are currently grouped in a single species, Cichlasoma minckleyi, which is believed to display marked trophic polymorphism. I investigated Cuatro Cienegas cichlid morphology to determine number of morphs and identify characters contributing to differences between them. I also report results of experiments designed to assess the relative roles of genetics and environmentally-induced plasticity in producing trophic morphology. I identify two distinct morphs of Cuatro Cienegas cichlids distinguished largely by features of the trophic apparatus, especially the pharyngeal dentition. Variation in body shape is continuous and does not allow recognition of discrete forms, though this conclusion is inconsistent with previous studies and is currently being tested with more sensitive (geometric morphometric) methods. Individuals raised in the laboratory on several different diets indicate that trophic morphology has an important genetic component. However, individuals representing both morphs raised in the lab did not differentiate to the degree seen in comparably sized individuals collected at Cuatro Cienegas. This may be due to differences in hardness between endemic snails and those used as food in the experiments, and indicates that some aspects of trophic morphology are also dependent upon environmental cues. (Session P-14, Saturday, July 7, Penn Stater, Deans Hall)

TROLL, RAY
P.O. Box 8874, AES, Ketchikan, AK 99901
The True Tale of How Paleozoic "Sharks" Came to Rule my Life and Art
I will be presenting an illustrated informal talk about how fish came to dominate my artwork since moving to Alaska 20 years ago and more specifically how Paleozoic Chondrichthyans have recently dominated my illustration work.
This work includes various museum installations I have worked on, Discovery Channel films, and magazine assignments.
I have worked for the past year on a suite of new shark drawings that I will "debut" in my slide talk. The drawings have been produced for a book to be published early next year.
For more information on my work look at www.trollart.com (Session 26, Monday, July 9, Penn Stater, Room 207, 11:30)

TURNER, GEORGE F.
HU6 7RX, United Kingdom, University of Hull, United Kingdom, United Kingdom HU6 7RX United Kingdom
How Many Species of Cichlid Fishes are there in African Lakes?
The endemic cichlid fishes of Lakes Malawi, Tanganyika and Victoria are textbook examples of explosive speciation and adaptive radiation. Accurate estimates of species richness of lineages in these lakes, and elsewhere, will be a necessary prerequisite for analysis of the factors influencing rates of diversification. This review presents recent findings on the discoveries of new species and species flocks and critically appraises the relevant evidence on species richness from recent studies of polymorphism and assortative mating, generally using behavioural and molecular methods. Studies to date indicate that estimates of alpha (within-site) diversity appear to be robust. Overall estimates of species richness in Lakes Malawi and Victoria are heavily dependent on the assignation of species status to allopatric populations differing in male colour. Appropriate methods for testing the specific status of allopatric cichlid taxa are reviewed and preliminary results presented. (Session 6, Saturday, July 7, Penn Stater, Pres I Hall)

*TYMINSKI, JOHN P., SIMPFENDORFER, COLIN A., MANIRE, CHARLES A., HUETER, ROBERT E.
1600 Ken Thompson Parkway, Mote Marine Laboratory, Sarasota, FL 34236
Growth rates of bonnethead sharks, Sphyrna tiburo, from the west coast of Florida estimated from tag-recapture data.
The growth of bonnethead sharks off the west coast of Florida was investigated using tag-release-recapture methods. Juvenile and adult bonnetheads were tagged with external nylon-barbed tags and released along Florida's Gulf coast beginning in November of 1991. Growth data were obtained from 113 tag recaptures, 70 of which were recaptured by Mote Marine Laboratory biologists. The time at liberty ranged from 1 to 2029 days while the measured growth increments ranged from -5.5 to 30.5 cm. A maximum likelihood approach was employed to analyze these growth increment data. In addition to von Bertalanffy parameters, this method allows for an estimation of measurement error, growth variability, and treats data outliers objectively. A bootstrapping method was utilized to estimate confidence limits of the parameters. When combining all usable samples from all areas, Linf and K were estimated at 104.3 (cm STL) and 0.28 year ± 1, respectively. A subset of female-only recaptures from Tampa Bay produced comparable growth parameters (Linf= 105.4 and K= 0.28 year ± 1). The results will be discussed and compared with published results from age-at-length data for bonnetheads inhabiting similar regions in Florida. (Session 10, Saturday, July 7, Penn Stater, Room 207, 3:00)

TZILKOWSKI, CALEB J.
Forest Resources Laboratory, The Pennsylvania State University, University Park, PA 16802
Diet and Reproductive Biology of the Northern Madtom, Noturus stigmosus in French Creek, Pennsylvania
The Northern madtom, Noturus stigmosus, is listed as threatened by the Pennsylvania Fish and Boat Commission (PAFBC) and little is known of its reproductive biology and diet. I collected 29 N. stigmosus from a 100 m reach of French Creek near Venango, Pennsylvania on June 15, 1999 as part of the PAFBC's development of an index of biological integrity. Standard length (SL) and weight of N. stigmosus varied from 59.22 - 85.15 mm and 2.83 - 9.28 g, respectively. From the 26 females collected, SL and weight were more strongly correlated to total number of eggs (r = 0.65; 0.67) than average egg diameter (r = 0.38; 0.49). I identified and counted the stomach contents from the collected N. stigmosus. Furthermore, I collected 29 of the ubiquitous and sympatrically occurring stonecat, Noturus flavus from which stomach contents were identified and enumerated. Diet selectivity and overlap of N. stigmosus and N. flavus were determined using the Strauss and Schoener's indices. Noturus stigmosus preferred Blackfly (Simulidae) and Stonefly (Perlinella spp. i) larvae, avoided midge (Chironimidae) and beetle (Elmidae) larvae, and were in competition with N. flavus for food. (Session 17, Sunday, July 8, Penn Stater, Room 206, 8:15)

*UGARTE, CRISTINA A., RICE, KENNETH G.
(CAU) University Park, Florida International University, Miami, FL 33199; (KGR) USGS-Everglades National Park, USGS/BRD-Restoration Ecology Branch, Homestead, FL 33034
Abundance estimation of pig frogs Rana grylio using a double observer approach
Baseline abundance data on amphibians are lacking. Given the current decrease in populations worldwide, it is essential to have accurate abundance estimates of amphibian populations. When sampling animal populations, two forms of variation can bias abundance estimates, spatial variation and detectability. Detectability estimates are affected by observer experience, weather conditions, and changes in habitat over space and time. Most surveys however do not account for these differences. We use a modified double observer approach to estimate detection probabilities and abundance (Nichols et al 2000). This is the first time this method is used to estimate amphibian abundances. Two observers, a primary observer and a secondary observer count frogs along 15 one kilometer transects in long hydroperiod marshes of south Florida. The role of the primary observer is to count and point out frogs seen within a 10 meter strip of the airboat trail. The secondary observer records the number of frogs missed by the primary but seen by the secondary observer. Each observer alternates these roles per transect. The program SURVIV is used to compare differences in detection between observers. A total of 45 transects, 15 in each of three large areas were surveyed (two harvested sites, one unharvested site) in south Florida from August 2000 to June 2001. Temporal differences and observer differences in detectability were evident. (Session 30, Monday, July 9, Penn Stater, Room 206, 11:15)

*UNMACK, PETER J., HAMMER, MICHAEL, ADAMS, MARK, DOWLING, THOMAS E.
(PJU, TED) Biology Department, Arizona State University, Tempe, AZ 85287; (MH) Department of Environmental Biology, University of Adelaide, Adelaide, South Australia 5005 Australia; (MA) Evolutionary Biology Unit, South Australian Museum, Adelaide, South Australia 5000 Australia
Phylogenetic relationships, hybridisation, and biogeography within the Australian pygmy perches (Percichthyidae).
Pygmy perches are small freshwater fishes (rarely exceeding 10cm in length), with a restricted distribution in southeastern and southwestern Australia. Historically considered part of the Kuhliidae, and subsequently a unique family Nannopercidae, they have recently been included in the Percichthyidae, a decision supported by published 12S sequence data for percichthyids. This presentation summarizes the results of two companion molecular studies on the group, one using allozyme data at 50 loci to assess species boundaries in the group and population structure within widespread species, and the other examining relationships within Percichthyidae and among basal percoid families using mitochondrial and nuclear sequence data (cytochrome B, S7, RAG2). Both studies utilize many of the same specimens and include all pygmy perch species as well as an in-depth examination of the two most-widespread morphospecies N. australis and Edelia obscura. Although both studies are ongoing, several unequivocal conclusions are nevertheless evident. First, Nannoperca australis clearly comprises two species with largely parapatric distributions, but with a single instance of introgression in southeastern Victoria. Second, the specific status of all other named forms is supported. Third, all phylogenetic analyses of the mtDNA data indicate that the more-widespread species within N. australis is paraphyletic with respect to E. obscura, suggesting either that mitochondrial replacement has occurred between these species or that insufficient time has transpired for both species to move to reciprocal monophyly. Fourth, there appears little support for retaining Edelia as a separate genus. These results, and phylogenetic relationships of the group will be placed into a broader Australian biogeographic context. (Session 36, Tuesday, July 10, Penn Stater, Room 208, 9:30)

*VAN TASSELL, JAMES L., ZARDOYA, RAFAEL, RUBER, LUKAS
(JLV) 27 Plitt Ave, Hofstra University, Farmingdale, NY 11735; (RZ, LR) Jose Gutierrez Abascal 2, Museo Nacional de Ciencias Naturales, Madrid, Madrid 28006 Spain
Molecular evidence on the phylogenetic relationships of the American Seven spined gobies
The Gobiosomini, was originally proposed by Birdsong (1975) and later revised by Birdsong et al. (1988), to unite what was commonly called the American seven-spined gobies and several closely allied genera, all endemic to the New World. Past classifications of the group have divided Gobiosoma into a variety of subgenera or genera depending on the characters deemed important, but the phylogenetic relationships within the group remain controversial based on morphological evidence. Here, we present a molecular phylogeny of the Seven spined gobies based on almost complete mitochondrial 12s and 16s gene sequence data. Two main clades are consistently formed. One clade consisting of Elacatinus, Tigrigobius, Risor, and Ginsburgellus and the other consisting of Gobiosoma, Enypnias, Gobiolepis, Barbulifer, and Aruma. The genera Aboma, Chriolepis, and Nes are basal to the Elacatinus + Gobiosoma clade. Comparisons between the mtDNA phylogeny and the one proposed by Van Tassell (1998) based on morphology will be discussed along with an assessment of character distributions and the biogeography and ecology of the group. (Session 35, Tuesday, July 10, Penn Stater, Room 108, 8:30)

"VERHEYEN, ERIK
Vautierstraat 29, Royal Belgian Institute of Natural Sciences, Belgium, Europe
Spatial and temporal patterns in the evolution of the cichlid species assemblages of the East African lakes.
Recent phylogenetic studies provide new information on spatial and temporal aspects of the evolution of cichlid species assemblages of the lakes Tanganyika, Malawi and Victoria. The discovery of parallel evolution of taxonomically important features suggests that the intralacustrine evolution of rock-dwelling cichlids may be more complex than assumed. Lake level fluctuations resulting in the alternating presence and absence of barriers to gene flow had a major impact on the intralacustrine speciation of cichlids and the current distribution ranges of their populations and mtDNA haplotypes. Phylogeographic patterns in rock-dwellers differ from the ones observed for benthic and pelagic cichlid species and confirms that these ecological groups were not similarly affected by these events. Moreover, differences in breeding behaviour result in different phylogeographic patterns and amounts of gene flow between adjacant populations of closely related rock-dwellers from Lake Tanganyika, as well as for cichlids from similar habitats from Lake Malawi. Finally, phylogeographic data for representatives of rock-dwelling cichlids of the three lakes suggest that the last major low water level must have occurred almost simultaneously. The significance of the impact of this event on these faunas and the significantly different recovery of the faunas for these three lakes will be discussed. (Session 6, Saturday, July 7, Penn Stater, Pres I Hall)

*VETTER, RUSSELL D., BUONACCORSI, VINCENT P., KIMBRELL, CAROL A., LYNN, ERIC A.
(RDV, VPB, EAL) 8604 La Jolla Shores Drive, National Oceanic and Atmospheric Administration, La Jolla, CA 92037; (CAK) 8604 La Jolla Shores Drive, Southwest Fisheries Center, La Jolla, CA 92037
Conservation genetics of west coast rockfishes, genusSebastes
Populations of many west coast rockfish species are severely depleted and some have been petitioned as candidates for protection under the Endangered Species Act (ESA). Puget Sound populations of copper rockfish, Sebastes caurinus, quillback rockfish Sebastes maliger, and brown rockfish, Sebastes auriculatus are presently being considered and a petition to list bocaccio rockfish Sebastes paucispinus has been received. The Act provides for protection of Distinct Population Segments (DPSs) as well as entire species. Genetic differences are one of the more compelling and quantitative reasons for considering a population as a DPS but there should be evidence that the DPS contains significant phenotypic differences whose loss would be detrimental to the evolutionary legacy of the species. A group of 7 polymorphic microsatellite loci have been developed and have proved informative for examining population genetic structure, oceanographic larval dispersal patterns, and barriers to gene flow in rockfish populations from Baja California, Mexico to Alaska. Results from species that are benthic and sedentary as adults such as copper rockfish, grass rockfish, S. rastrelliger, and gopher rockfish, S. carnatus are compared to more vagile species such as bocaccio and widow S. entomelas. Pelagic larval dispersal patterns along the open coast and within the confined regions of the Puget Sound will be discussed in relation to the DPS criteria of the ESA. (Session 38, Tuesday, July 10, Penn Stater, Room 207, 2:00)

*WAGNER, MICHAEL, MACLEAN, AMANDA, WEATHERBEE, JAMIL
(MW) Warnell School of Forest Resources, University of Georgia, Athens, GA 30602; (AM) Division of Environmental & Evolutionary Biology, University of Glasgow, Glasgow, G12 8QQ Scotland; (JW) 1990 Olivera Road, Acro Associates, Inc., Concord, CA 94520
Performance of an automatic feeder for the delivery of natural prey items during controlled multi-patch behavioral experiments with drift-feeding stream fishes.
Laboratory foraging experiments often require the ability to directly manipulate the spatial and temporal availability of prey. In small-scale or short-term experiments with fishes this may be accomplished by dispensing individual prey items by hand. However, automated methods are required when known amounts of food must be delivered to multiple sites or over protracted periods. We have designed an automated feeder system to dispense natural prey (chironomid larvae) to drift-feeding stream minnows in a laboratory stream tank. The feeder supplies prey to a maximum of four patches, at rates which may be set individually for each patch, and may be adjusted as often as required. Prey items are kept in suspension in a 17-L brine shrimp hatching tank via aeration. A stand-alone controller (programmable dual-mode repeat cycle timer) operates pinch valves, which open and close according to operator settings, thus controlling the flow of water carrying food to a patch. The feeder has been designed for two- or four-patch experiments but could easily be modified to accommodate several patches. Performance data are presented for frozen commercially available chironomid larvae. (Session P-32, Monday, July 9, Penn Stater, Deans Hall)

*WALSH, CATHY J., TORANTO, JASON D., BODINE, A. B., LUER, CARL A.
(CJW, JDT, CAL) 1600 Ken Thompson Parkway, Mote Marine Laboratory, Sarasota, FL 34236; (ABB) 131 Poole Agricultural Center, Clemson University, Clemson, SC 29634
Production of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) by peripheral blood leukocytes from nurse sharks Ginglymostoma cirratum
Nitric oxide (NO) is a potent cytotoxic molecule that serves as an antipathogenic agent in cell-mediated immune responses of higher vertebrates. Its production in immune cells results from the enzymatic transformation of L arginine to L-citrulline by the inducible isoform of nitric oxide synthase (iNOS). To establish whether elasmobranchs produce reactive nitrogen intermediates, NO production by nurse shark Ginglymostoma cirratum peripheral blood leukocytes (PBL) stimulated with bacterial lipopolysaccharide (LPS) was investigated. Nurse shark PBL (6.25x105, 1.25x106, and 2.5x106 cells/mL) were cultured for 24 to 96 h following stimulation with 0, 2.5, 5, 10, or 25 ug/mL LPS, in both serum supplemented (fetal bovine serum, FBS, and nurse shark serum, NSS) and serum-free culture conditions. Production of NO was measured indirectly via nitrite detection using the Griess reaction. Maximal NO production was observed after 72 h using a PBL concentration of 2.5x106 cells/mL cultured with 10% FBS and stimulated with 10 ug/mL LPS. When PBL were cultured with a specific inhibitor of iNOS, the arginine analog L-N6-(1 iminoethyl)lysine (L-NIL), production of NO was inhibited. Procedures to confirm the presence of iNOS, which rapidly degrades in cell lysates, are being developed for Western blot analysis. (Session 20, Sunday, July 8, Penn Stater, Room 207, 2:00)

WALTERS, ELIZABETH J.
224 Arts II, The Pennsylvania State University, University Park, PA 16802
Ancient Greece: Tall but deadly fish 'tails'
The wine dark sea of Homer still conveys the majesty and power of the seemingly limitless water surrounding Greece. This paper explores Greek and Roman values with regard to deadly encounters at sea, and aggressive attacks inspired from predators such as sharks. This investigation identifies the poet Homer as invaluable, stimulating the arts of his time (eighth century B.C.) and inspiring monumental works 700 years later in Greece and monumental acclaim by the first century A.D. In particular, murals for estates in Rome in the first century B.C. involved seascapes of Homer's Odyssey. This tale involved the arduous return home from ancient Troy, and sudden death in several places and at sea that wiley Odysseus barely escaped. Sea monsters include the Scylla who grew immeasurably in the arts by the first century A.D. to command the attention of the emperor Tiberius in an imperial estate with sea grotto at Sperlonga south of Rome. Rhodian artists used the Scylla as their signed centerpiece, and best conveyed the ferocity of the combined physical forms and aggression, while permitting the viewer, the emperor to live as dangerously as Odysseus. (Session 26, Monday, July 9, Penn Stater, Room 207, 8:30)

WEAVER, DOUGLAS C.
7922 NW 71st Street, University of Florida, Gainesville, FL 32653
Trophic Subsidies in the Twilight Zone: Zooplankton Community Patterns and Food Web Structure of Deep Reef Fishes in the Northeastern Gulf of Mexico.
The food web structure and prey encounter rates of deep (50-110m) reef fishes in the northeastern Gulf of Mexico was examined. Fish communities on high profile topographic features at the edge of the continental shelf and upper continental slope are numerically dominated by two species of streamer basses (Serranidae: Anthiinae): the roughtongue bass, Pronotogrammus martinicensis, and the red barbier, Hemanthias vivanus. Stomach content analysis revealed that calanoid copepods, pteropods, pelagic tunicates, and invertebrate larvae dominate the diets of both species, and that these small plantivores serve as primary prey for many larger reef predators. To compare diets of reef fishes with pelagic prey availability and encounter rates, stationary plankton tows (0.5m diameter, 335m mesh conical nets) were made in the water column at near surface (2m), midwater (35m) and near-reef (60-70m) depths. Preliminary results indicate high flow rates (4-24 cm/sec, mean=15.6cm/sec) and high prey availability (16 to 124 zooplankters/m3) in the vicinity of deep reef features. Estimates of the relative abundance of fishes indicate that 99% by number and 90% of the biomass of resident species are small planktivores, and 65-90% of their diets are calanoid copepods, forming the main link from the benthos to water column productivity and the primary source of prey for the demersal reef fish community. (Session 17, Sunday, July 8, Penn Stater, Room 206, 9:30)

*WEBB, JACQUELINE F., KELLY, NATASHA, CICCHINO, NICOLE
Mendel Hall, Villanova University, Villanova, PA 19085
Ontogeny of the laterophysic connection, a novel swim bladder-lateral line connection, in larvae and juveniles of the Caribbean butterflyfish, Chaetodon ocellatus.
The laterophysic connection (LC) in Chaetodon is defined by paired, anterior swim bladder diverticula ("horns") that are in direct contact with, or in proximity to, medial openings in the supracleithral lateral line canals. It is thought that the LC makes both the ear and lateral line system pressure sensitive. The goal of this study was to describe LC development histologically in order to hypothesize how sensory capabilities may change ontogenetically in Chaetodon. Chaetodon ocellatus were collected in minnow traps at the Rutgers University Marine Field Station (Tukerton, NJ). Tholichthys and juveniles (15-42 mm SL, n=15) were embedded in glycol methacrylate resin and sectioned transversely at 5 microns. Medial supracleithral opening size increased linearly with fish size. Horns first appear as small protrusions in the anterior swim bladder wall in individuals <25 mm SL. Distinct cylindrical horns form at 25-29 mm SL, approach the medial supracleithral opening in individuals >30 mm SL. Transformation from the pelagic (tholichthys) to the benthic juvenile stage occurs in smaller indivduals (20-22 mm SL, McBride and Able, 1998). We conclude that a LC is a post-metamorphic feature, and hypothesize that its presence enhances pressure sensitivity only in benthic juveniles in Chaetodon. (Session P-14, Saturday, July 7, Penn Stater, Dean Hall)

*WIENS, JOHN J., SLINGLUFF, JAMIE L.
Carnegie Museum, Carnegie Museum of Natural History, Pittsburgh, PA 15213
How lizards turn into snakes: a phylogenetic analysis of body form evolution in anguid lizards
The transition between lizard-like and snake-like body form is dramatic and common in squamates, but has never been studied using statistical phylogenetic methods. We examine the evolution of body form in anguid lizards, a clade in which there have been multiple independent losses of limbs. Using a molecular phylogeny, morphometric data, and phylogenetic comparative methods, we confirm the hypothesized relationships between body elongation and limb reduction and between limb reduction and digit reduction. However, in contrast to predictions of previous authors, there is no clear sequence going from body elongation to limb reduction to digit loss, and a burrowing lifestyle is not a necessary correlate of limb loss. We also show that similar degrees of overall body elongation are achieved in two different ways in anguids, that these modes of elongation are associated with different microhabitat preferences, and that this dichotomy in body plan and ecology is widespread in limb-reduced squamates. Finally, a recent developmental study has suggested that the transition from lizards to snakes involved changes in the expression of Hox genes that led to sudden, linked morphological transformations. Our results suggest instead that this transition involved correlated changes in body form occurring gradually over very long time scales. (Session 18, Sunday, July 8, Penn Stater, Room 208, 11:15)
WILEY, E. O.
Natural History Museum, University of Kansas, Lawrence, KS 66045
Building a Distributed Information System, FishNet, for Ichthyology
Natural History collections contain the most comprehensive description of biodiversity on earth. Until recently, extracting this information and using it has been difficult, even when the collections are computerized. New technologies are permitting ichthyologists and others to gain access to museum data on a world-wide scale (e.g., The Species Analyst) and other new technologies are allowing us to synthesize and analyze these data in novel ways (e.g., GARP). In this poster, I will review these new technologies and show how they can be used to study different aspects of both biogeography and ecology. I will also review progress on building the FishNet distributed network, a partnership of over 20 fish collections who have agreed to share data. (Session P-24, Saturday, July 7, Penn Stater, Deans Hall)

WILEY, E. O.
Natural History Museum, University of Kansas, Lawrence, KS 66045
On Species and Speciation
Biologists who study the speciation process do so within the constraints of specific concepts of what constitutes a species. Consideration of speciation as a process influences the species concept adopted. Pattern and process are not separate but intertwined in a spiral of scientific understanding Hennig called reciprocal illumination and what many philosophers simply call scientific progress. The broad pattern of speciation in fishes where we have sufficient phylogenetic information is a pattern of allopatry between closest relatives. This phenomenon, recognized by A. Wallace in the 1850s, suggests that allopatric speciation is the most common mode of speciation among these fishes. There seems to be no particular "driving force" behind speciation other than geographic subdivision and the consequences of this subdivision. Since allopatric speciation seems to occur within a community context largely unchanged by the allopatric event, there need be no a priori expectation that sister species will have different behaviors, ecologies, or any other class of changes in their characteristics. This is reflected in the empirical record; what actually changes during evolutionary descent within clades is unpredictable relative to changes that occur between clades that have speciated in the same place and time. (Session 2, Friday, July 6, Penn Stater, Room 105, 2:30)

WILKENS, HORST
Martin-Luther-King-Platz 3, University of Hamburg, Hamburg D-20146 Germany
Convergence of Astyanax cave fish evolution: Genetic evidence from eye reduction
More than 20 cave populations of the characid Astyanax occur within a rather restricted karst area in Mexico. They possess reduced eyes without lenses and visual cells. It is still an open question whether eye reduction in these cave fish has convergently evolved after multiple entries of the surface ancestor into the different caves or if a single cave ancestor already characterized by reduced eyes has secondarily spread into the various caves. In the F2-crosses between specific cave populations specimens appear, which considerably deviate from those of the cave parents. They possess larger and better developed eyes with histologically intact lenses and visual cells. This states former results, which revealed that not the destruction of structural genes but above all that of developmental control genes is responsible for eye reduction in cave fish. It can be concluded that in different cave populations different mutations in the control gene system have happened. In case these non functional control genes are recombined in F2-specimens gene expression is restored again. Larger eyes - some of them even functional - are developed. This is the result of convergent evolution of the Astyanax cave populations. (Session 12, Saturday, July 7, Penn Stater, Room 208, 11:45)

*WILKENS, HORST, STRECKER, ULRIKE
Martin-Luther-King-Platz 3, University of Hamburg, Hamburg D-20146 Germany
Impact of introduced species on the endemic Cyprinodon species of Laguna Chichancanab
The Laguna Chichancanab has about 5 o/oo salinity and lies at the level of the "species minimum" in the salinity gradient scale. These extreme abiotic conditions allow few species to exist in the lake. The original fish spectrum was limited to the poeciliid Gambusia sexradiata and an endemic Cyprinodon species flock. Due to the hurricanes Gilberto (1988) and Roxana (1995) new fish were introduced. In 1988 exotic cichlids escaped from aquacultural facilities and in 1995 the Mexican Astyanax (Characidae) appeared. Both species developed extremely high abundances. Except C. simus which no longer was observed forming schools, the population density of the Cyprinodon species did not notably decline during the exclusive presence of the cichlids. This can be explained by the sediment feeding cichlids exploring a niche not occupied by the species flock. The appearance of Astyanax, however, was followed by a lowering of the abundances of the species flock. This is probably caused by Astyanax preying on iuvenile Cyprinodon and cichlids, which also seem to decrease. Except for C. simus all other members of the species flock still exist. Following the cichlid mass development the Cyprinodon showed an increase of infestation by parasites, the final hosts of which are fish preying birds. (Session 33, Tuesday, July 10, Penn Stater, Pres I Hall)

*WILSON, JOSEPH J., MARET, TIMOTHY J.
(JJW) P.O. Box 67100, Gannett Fleming, Inc., Harrisburg, PA 17106; (TJM) 1871 Old Main Drive, Shippensburg University, Shippensburg, PA 17257
The feeding ecology of three sympatric larval Ambystoma in temporary ponds from south-central Pennsylvania
Previous studies indicate that ambystomatid salamanders are zooplankton specialists and gape limited predators that compete heavily for resources. We studied the coexistence of three sympatric larval Ambystoma in temporary ponds from south-central Pennsylvania. We performed a three-year survey of the larval salamander population numbers, diets, and growth rates as well as the zooplankton abundance of resident temporary ponds. We found that crustacean zooplankton were a substantial portion of the diets of the species we studied but we also found that diets varied considerably among species, among different habitat conditions, and temporally. For example, a large proportion of the diet of Ambystoma opacum contained terrestrial and aquatic insect prey, especially when sharing ponds with other Ambystoma. Furthermore, A. jeffersonianum tended to specialize on zooplankton early in the season and included a substantial amount of vertebrate prey in their diet as the season progressed. A. maculatum, the smallest of the ambystomatid larvae in the ponds at any given time, tends to specialize on zooplankton even as its size increases. Our findings provide new evidence into the diets and co-existence of these species. (Session 17, Sunday, July 8, Penn Stater, Room 206, 8:30)

*WITTE, FRANS, SEEHAUSEN, OLE, GOLDSCHMIDT, TIJS, WANINK, JAN H.
(FW, TG, JHW) P.O.Box 9516, Institute of Evolutionary and Ecological Sciences, University of Leiden, Leiden 2300 RA The Netherlands; (OS) University of Hull, Hull, Yorkshire HU6 7RX U.K.
Cichlid species diversity, reproductive strategies and environmental parameters in Lake Victoria
Diversity of cichlid species in Lake Victoria differs with habitat. The number of species is 1.5 times higher over sand than over mud bottoms of comparable depth. We surveyed environmental and biological parameters that may explain these differences. Many cichlids in shallow sandy and rocky habitats spawn year-round, whereas the spawning of most mud dwelling species is strongly seasonal. Mud bottoms in Lake Victoria are covered with a thick layer of organic ooze, which can easily stir-up. These layers are hypoxic, restrict light penetration close to the bottom and seem unsuitable for making spawning pits. Oxygen concentration is likely to impact on reproductive strategies. Indeed, a strong negative correlation was found between dissolved oxygen and egg size in a number of species. However, spawning peaks over muddy bottoms and in deep water correlate to periods with high water transparency rather than to periods with high oxygen concentrations. Earlier research revealed that high water transparency is crucial for maintaining reproductive isolation between species in sympatry. This could explain higher species packing in shallow, sandy habitats, though other factors, such as possibilities to spawn year-round, may contribute as well. (Session 15, Sunday, July 8, Penn Stater, Pres I Hall)

*WONG, RICHARD A., TARGETT, TIMOTHY E.
700 Pilottown Road, University of Delaware, Graduate College of Marine Studies, Lewes, DE 19958
Nursery habitat use by young-of-the-year tautog (Tautoga onitis): behavioral preferences for submerged macrophytes (macroalgae and eelgrass (Zostera marina)) and hard-structure
The tautog, T. onitis, is a large, temperate labrid, that depends on structured habitat for all stages of its post-settlement life history. Adult tautog utilize hard-structured reef habitat, while young-of-the-year (YOY) are known to occur in submerged macrophytes (macroalgae and eelgrass (Zostera marina). However, there has been little direct exploration of the importance of reef habitat for YOY tautog; nor of preferences among macrophyte habitats. We designed a series of laboratory choice-experiments to investigate preferences among macroalgal species; macroalgae versus eelgrass; variable rock sizes; macroalgae versus rocks; and macroalgae-fouled rocks versus macroalgae alone. YOY tautog demonstrated a significant preference for Ulva and avoidance of Agardhiella in Experiment I. Ulva was significantly preferred over eelgrass. Of three rock sizes, the smallest rocks were significantly avoided. Ulva was significantly preferred over (medium-size) rocks. Ulva attached to rocks was significantly preferred over Ulva alone. Using SCUBA methodology, some YOY tautog were observed on estuarine reefs, yet no YOY tautog were detected on coastal reefs. The results of this investigation suggest that macroalgae is the most preferred nursery habitat for YOY tautog. Rock-structure (without macroalgal fouling) and eelgrass are secondarily preferred nursery habitats. (Session 27, Monday, July 9, Penn Stater, Room 206, 9:00)

*WOOD, ROBERT, GOEWERT, ANNE, KOPPELMAN, JEFF, SIMONS, ANDREW
(RW, AG) 3507 Laclede, Saint Louis University, St. Louis, MO 63103; (JK) 1110 S. College Avenue, Missouri Department of Conservation, Columbia, MO 65201; (AS) 200 Hodson Hall, University of Minnesota, St. Paul, MN 55108
Cytochrome b sequence variation in the flathead chub, Platygobio gracilis
The Flathead Chub, Platygobio gracilis is composed of two subspecies distinguished from one another on the basis of morphological criteria. We sequenced the cytochrome b gene of 20 individuals of flathead chub from throughout the species' range. Analyses revealed an average within population sequence divergence ranging from a low of 0.3% between individuals from the Loup River to a high of 2.2% between individuals from the Iowa tributaries of the Missouri River. Average between population sequence divergence ranged from a low of 0.4% between the Niobrara and Loup river samples and Loup and Cheyenne river samples, to a high of 5.9% between the Canadian River sample and the sample from the Rio Grande. Phylogenetic analysis of the 950 aligned bases for the 20 individuals (plus four outgroup taxa) sequenced in this study resulted in 18 equally most parsimonious trees at 595 steps (C.I. = 0.848, RC = 0.645). There is very little divergence among taxa and most individuals fail to group by either geographic location or existing subspecific taxonomy. These data and their implications for management of this species will be presented and discussed. (Session 12, Saturday, July 7, Penn Stater, Room 208, 11:30)

WOODLEY, CHRISTA M.
Gulf Coast Research Laboratory, The University of Southern Mississippi, Ocean Springs, MS 39566
Linking aquatic habitat loss to increased predation risk using measurements of respiratory metabolism and plasma cortisol.
Recent research has documented that fishes associated with submerged aquatic vegetation (SAV), shoals and other habitat structure may benefit from reduced predation risk. The loss of these structural habitats may increase individual stress levels of small fishes by the increased perception of predation risk. Oxygen consumption and cortisol concentrations are known to rise in fish in response to stressful stimuli. The objective of this study was to quantify the physiological responses of increased predation risk using metabolic rate, cortisol concentrations, growth, and behavior modification. Individual weight specific metabolic rate and cortisol concentrations of the prey fish (longnose killifish, Fundulus similis-majalis) exposed to a predator (sand seatrout, Cynoscion arenarius) were quantified using flow-through respirometry and EIA bioassay. Three treatments (SAV, no SAV, and blind controls) were randomly assigned around a central arena, which held a predator. We found significant reductions in oxygen consumption rate and cortisol concentration in treatments with less visual stimuli compared to the completely exposed treatments (all p< 0.001). In addition, there was a significant positive correlation between oxygen consumption rates and cortisol concentrations (p= 0.004). These experiments exemplify the importance of SAV or structural habitat to mediating the responses and stress levels of prey fish to a predator (Session 4, Friday, July 6, Penn Stater, Room 206, 4:45)

*WYFFELS, JENNIFER, BODINE, A. B., LUER, C. A., WALSH, C. J.
(JW, ABB) Clemson University, Clemson, SC 29634; (CAL, CJW) 1600 Ken Thompson Parkway, Mote Marine Laboratory, Sarasota, FL 34236
Acute radiation exposure in the clearnose skate, Raja eglanteria: A histological study of the thymus
Clearnose skate hatchlings (25g) were exposed to 0-75 Gray (1Gray = 100 rads) of ionizing radiation (n=122). The skates were sacrificed 10, 14, 20, 30 and 40 days post-irradiation. Thymii were fixed in 10% neutral buffered formalin and processed for routine histology. Fifty 3 micron cross-sections of thymus were collected at 50 micron intervals. Five thymus sections at 500 micron intervals weredigitized for area analysis. The averaged areas were expressed as a percent of the control and treatments compared with ANOVA. Beginning at 1.5 Gray there was a significant logarithmic decline in thymus area as a function of radiation dose that became asymptotic after 15 Gray. Histologically, the medulla was infiltrated with large cysts containing apoptotic thymocytes and eosinophils. There was a decrease in cellularity of the cortex evident after only 1.5 Gray. This decline continued until radiation levels reached 15 Gray, when only stromal connective tissue remained. Repopulation of the thymus began at day 30 after 9 Gray but was not yet complete after 40 days. In skates exposed to 13.5 and 18 Gray the thymus began to recover its cellularity on day 40. There was no significant increase in thymic area over the 40 day recovery period. (Session 20, Sunday, July 8, Penn Stater, Room 207, 2:15)

*ZAIDAN, FREDERIC, BEAUPRE, STEVEN J.
B2 Ferritor Bldg., University of Arkansas, Fayetteville, AR 72701
Specific dynamic action (SDA) in timber rattlesnakes (Crotalus horridus)
The analysis of mass and energy budgets provides insight into the ecology of individuals and populations. An important first step in constructing these budgets is to determine how much energy is required for meal processing. For sit and wait predators who down regulate the gut between feedings, the cost of SDA can be large. We studied the effects of snake mass, temperature (25 and 30C), fasting time (1 and 5 months), and prey size (10-50% of snake mass) on SDA in 26 timber rattlesnakes (Crotalus horridus). We used flow through respirometry to measure hourly CO2 production rates (VCO2) for one day before and 14 days after feeding. Crotalus horridus, like previously studied viperids and boids, shows large and ecologically relevant increases in metabolism due to feeding. VCO2 increased to 3.9-6.1 times resting metabolic rate within 17.2-36.1 hrs post-feeding and gradually decreased to baseline within 4.7-7.7 days. An ANOVA revealed that total CO2 produced (following correction for snake mass) over the entire SDA period was significantly higher at 30C (p=0.0006) and after a 5-month brumation period (p=0.0018). We use the prey size data to separate between fixed costs (gut upregulation) and variable costs (biochemical processing) of digestion. (Session 19, Sunday, July 8, Penn Stater, Room 105, 9:30)

*ZARDOYA, RAFAEL, MEYER, AXEL
(RZ) Jose Gutierrez Abascal, 2, Museo nacional de Ciencias Naturales, Madrid 28006 Spain; (AM) University of Konstannz, Konstanz 78457 Germany
On the origin of and phylogenetic relationships among living Amphibians
The phylogenetic relationships among the three orders of modern amphibians (Caudata, Gymnophiona, and Anura) were estimated based on molecular evidence. The complete mitochondrial genomes of a salamander (Mertensiella luschani) and a caecilian (Typhlonectes natans) were determined (16,656 and 17,005 bp, respectively), and compared with previously published sequences from a frog (Xenopus laevis) and several other groups of vertebrates. Phylogenetic analyses of the mitochondrial data supported with high bootstrap values the monophyly of living amphibians with respect to other living groups of tetrapods, and a sister group relationship of salamanders and frogs (the Batrachia hypothesis). These results are in agreemet with most morphological evidence. Strong support of the Batrachia hypothesis both from molecules and morphology provides a robust phylogenetic framework that may be helpful to comparative studies among the three living orders of amphibians (e.g. interpreting the considerably divergent vertebral, brain and digit developmental patterns found in frogs and salamanders). Additionally, the diapsid affinities of turtles (within the Amniota) are further supported in the complete mitochondrial tree. (Session 35, Tuesday, July 10, Penn Stater, Room 108, 9:30)