Abstracts for the 2010 Joint Meeting of Ichthyologists & Herpetologists
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Abstracts for the 2010 Joint Meeting of Ichthyologists & Herpetologists AES – American Elasmobranch Society ASIH – American Society of Ichthyologists & Herpetologists HL – Herpetologists’ League NIA – Neotropical Ichthyological Association SSAR – Society for the Study of Amphibians & Reptiles Providence, Rhode Island 7-11 July 2010 Edited by Martha L. Crump & Maureen A. Donnelly 2 May 2010 0705 Karel Liem Symposium II, Ballroom D, Friday 9 July 2010 Maria Abate, Melonie Lontoh, Magdalena Buttlar, Les Kaufman Boston University, Boston, MA, United States The Effect of Conspecific Alarm Cue on the Swimming Performance of Juvenile Nicaragua Cichlids (Hypsophrys nicaraguensis) Karel Liem catalyzed the study of adaptive plasticity in fish behavior, morphology, and their interplay. Predator-induced defenses include changes in activity and body form in response to alarm cues. The response entails a trade-off between crypsis and sustained swimming to evade pursuit. We exposed four-month- and six-month-old sibling Nicaragua cichlids from two different broods to alarm cue (conspecific skin extract) to test for a change in swimming performance. Distilled water was the control for cue delivery, and green swordtail (Xiphophorus hellerii) skin extract was the control for a response to any injured fish. Depth, standard length, and total length of siblings in all groups were equal prior to treatment. After at least four weeks of odorant treatment, individual fish were subjected to stepwise increases in current velocity in a flume until they fatigued (maximum trial time = 14 minutes). The time and velocity at fatigue was used to calculate critical swimming speed, a measure of swimming performance. The critical swimming speed of fish exposed to conspecific alarm cue was lower than those exposed to distilled water (Mann Whitney Us, P < 0.05). The critical swimming speed in green swordtail and distilled water treatments did not differ (P > 0.05). The perceived threat of predation conveyed by alarm cue is sufficient to affect fish stamina. The question is: was the response adaptive or merely a reflection of stress induced by the threat of predation? ________________________________________________________________________ 0326 HERPETOLOGISTS’ LEAGUE GRADUATE STUDENT AWARD, 556 AB, Friday 9 July 2010 Megan Acord, Carl Anthony, Cari-Ann Hickerson John Carroll University, Geneva, Ohio, United States Assortative Mating in the Polymorphic Salamander, Plethodon cinereus Reproductive isolation due to divergent selection is thought to be one of the means that promote speciation in sympatry. A key element of isolation is assortative mating. When studying speciation in sympatry, polymorphic taxa provide important model systems by focusing on reproductive isolation. We examined a polymorphic population of the red- backed salamander (Plethodon cinereus) for evidence of reproductive isolation through assortative mating. Our study population consists of two common color morphs, striped and unstriped. In the field, we turned over natural cover objects to find male-female pairs of P. cinereus during peak mating season. We recorded sex, color morphology, and snout-vent length (SVL) for each of the 100 pairs of salamanders found. Salamanders tended to mate assortatively in the field, but some intermorph pairings were observed. Such pairings interfere with the potential for divergence. Laboratory experiments were conducted to assess the ability of females of each color morph to distinguish between males of the same, and of different color morphs, through fecal squashing and scent. Results of the fecal pellet experiment were inconclusive, however in the scent experiment females tended to have a higher frequency of nose taps when exposed to males of the same color phase. ______________________________________________________________________________ 0216 Poster Session III, Exhibit Hall D, Sunday 11 July 2010 Andrew Adams, Nathan Landry, Michael Savaria, Whitney Hable, Ken Oliveira University of Massachusetts Dartmouth, Dartmouth, MA, United States A Comparison of Artificial Maturation of American Eels in Freshwater and Seawater Artificial maturation of male and female American eels, Anguilla rostrata, is becoming of greater importance as some evidence suggests the species is in decline. Preliminary research has shown male American eels can be matured in freshwater and that their sperm is capable of fertilization. Studies using the European eel, Anguilla anguilla, which are similar in their catadromous reproductive behavior, have shown that a higher sperm quality can be achieved from males if the eels are matured in seawater as opposed to freshwater. This study was designed to evaluate the role of maturation environment on sperm. Twenty silver phase male eels were divided, 10 per treatment, into freshwater and seawater groups. The freshwater group was maintained in a 450L recirculating freshwater tank while the seawater group was kept in a 500L flow through seawater system. All males were being artificially matured by weekly intraperitoneal injections of human chorionic gonadotropin (HCG). After 5 weeks of injections sperm was collected and measured for cell count, motility, and viability assays. These results will provide data that will enhance the understanding of artificial propagation of this species. ______________________________________________________________________________ 0289 Poster Session II, Exhibit Hall D, Saturday 10 July 2010 Andrew Adams, Nathan Landry, Michael Savaria, Ken Oliveira, Whitney Hable University of Massachusetts Dartmouth, Dartmouth, MA, United States Polychlorinated Biphenyls Cause Sperm Deformities in the American Eel The American Eel is considered to be in a state of population decline. Contamination has been hypothesized to be one of several possible causes that may be contributing to the reduction in recruitment to continental waters. Polychlorinated biphenyls (PCBs) are a common pollutant that accumulates to high levels in the American eel. Eels do not feed during their extensive migration to the spawning area and thus metabolize stored lipids as an energy source. These lipids are also the primary location for sequestered PCBs, and the migration likely releases PCBs into the eels’ circulation during gametogenesis. Evidence from avian and mammalian systems indicates that PCBs can affect the structure of sperm heads and flagella. Moreover, a recent study has shown that American eels treated with PCBs yield sperm with decreased motility. The current study was designed to determine if low levels of circulating PCBs disrupt spermatogenesis in the American eel. Eels were injected weekly with 1.0 or 10.0 µg of a mixture of Aroclors 1221, 1242, and 1254 while being artificially matured with injections of human chorionic gonadotropin. After 5 weeks, milt was examined for cell count, sperm motility, viability, and microtubule structure within the flagella. Preliminary results show that eels treated with high concentrations of PCBs produce sperm with deformed sperm heads, often lacking microtubules within the flagella. These results will provide insight into the often overlooked effect of contamination on the male contribution to reproduction. 0208 Herp Conservation II, Ballroom B, Sunday 11 July 2010 Cory Adams, Daniel Saenz Southern Research Station, Forest Service, U.S. Department of Agriculture, Nacogdoches, Texas, United States The Effects of Chinese Tallow (Triadica sebifera) on Lithobates sphenocephalus Hatching Chinese tallow (Triadica sebifera) is a subtropical deciduous tree native to China and Japan. It was first introduced into the United States in the late 1700s and in Texas in the early 1900s. Chinese tallow is extremely abundant in parts of eastern Texas and has the capability of producing monocultures which can be in or near wetlands that are utilized by breeding amphibians. The impact Chinese tallow has on most amphibians is currently unknown. We determined if Chinese tallow has an effect on the hatching of a common anuran, Lithobates sphenocephalus. We found that Chinese tallow leaf litter significantly affects dissolved oxygen, pH, and turbidity. At low concentrations, Chinese tallow can be lethal to L. sphenocephalus eggs. We determined that by controlling dissolved oxygen, eggs exposed to low concentrations of Chinese tallow hatched, but died in higher concentrations. We also found that at low concentrations Chinese tallow significantly reduced the time to hatching, and had similar effects as red maple (Acer rubrum), a native tree species. Since Chinese tallow appears to negatively affect water chemistry, this non-native species could be a significant threat to amphibians. 0577 Poster Session I, Exhibit Hall D, Friday 9 July 2010 Dominique Adriaens1, Renaud Boistel2, Barbara De Kegel1, Joachim Christiaens1, Manuel Dierick3, Luc Van Hoorebeke3 1Ghent University, Gent, Belgium, 2CNRS/Université de Poitier, Poitier, France, 3Ghent University, Gent, Belgium On How to Reconcile Flexibility with Rigidity during Evolution: The Caudal System in Seahorses Within teleosts, seahorses and pipefish are unique fishes that are capable of using their caudal tail as a prehensile organ. An unusual level of flexibility for such a system in teleosts, paradoxally, evolved within a lineage in which the body is covered with bony plates. This provides at least in pipefish an increased level of rigidity, as well as protection against predators. It thus seems that evolutionary transformations of the caudal system within syngnathid fishes resulted