Development and characterization of 16 microsatellite markers for the Louisiana pine snake, Pituophis ruthveni, and two congeners of conservation concern

We isolated and characterized 16 microsatellite loci from the Louisiana pine snake, Pituophis ruthveni. Loci were screened in 24 individuals from locations throughout its distribution in Louisiana and Texas. The number of alleles per locus ranged from 4 to 12, observed heterozygosity ranged from 0.200 to 0.875, and the probability of identity ranged from 0.043 to 0.298. We examined cross-species amplification at these loci in P. catenifer (bullsnakes and gopher snakes) and P. melanoleucus (pine snakes). These new markers provide tools for examining the conservation genetics of this species complex. Louisiana pine snakes face numerous threats: population densities are extremely low and their natural habitat has been severely altered and fragmented. In southern Canada, P. catenifer is at the northern extreme of its range and limited by the availability of suitable over-wintering sites. Hence, for these two species reduction of heterozygosity, potential for inbreeding, and increased effects of genetic drift are all of considerable conservation concern

Sequencing three crocodilian genomes to illuminate the evolution of archosaurs and amniotes

The International Crocodilian Genomes Working Group (ICGWG) will sequence and assemble the American alligator (Alligator mississippiensis), saltwater crocodile (Crocodylus porosus) and Indian gharial (Gavialis gangeticus) genomes. The status of these projects and our planned analyses are described

Data package including genotypes, parentage assignment, and associated data

This Excel workbook includes four worksheets that include the microsatellite genotypes for adults and offspring ("G. polyphemus Genotypes", candidate sire ID's with associated siring and size data used in the ZIP analysis ("Candidate Sires+Assoc Data"), the candidate dam ID's used for this analysis ("CandidateDams"), and the final assigned parentage for hatchlings in this analysis ("AssignedParentage"). All column headers included comments that provide further information on the data they contain

Data from: Male body size predicts reproductive success but not within-clutch paternity patterns in gopher tortoises (Gopherus polyphemus)

In many vertebrates, body size is an important driver of variation in male reproductive success. Larger, more fit individuals are more likely to dominate mating opportunities, skewing siring success and resulting in lower effective population sizes and genetic diversity. The mating system of the gopher tortoise (Gopherus polyphemus) has been characterized as both female-defense and scramble-competition polygyny. Mating systems are typically not fixed and can be influenced by factors such as population density, demographic structure, and environmental conditions; however, most populations will have a predominant strategy that results from local conditions. We assessed how male body size influences patterns of paternity and reproductive success in a natural population of gopher tortoises in Florida, USA. Using microsatellites, we assigned parentage of 220 hatchlings from 31 nests collected during two reproductive seasons. Larger males were significantly more likely to sire offspring and sired more offspring than smaller males; however, the likelihood of a clutch being multiply-sired was unrelated to male body size. We also found evidence of mate fidelity across years. Although paternity patterns in this high-density population are more consistent with defense polygyny, female monopoly by males was incomplete, with both large and small males contributing to multiply-sired clutches. Additional behavioral data are needed to clarify the role of female mate selection in paternity outcomes. The context-dependence of mating systems underscores the need to compare parentage patterns across populations and to recognize the potential for more than one strategy to be employed within a single population

Effects of Copper on Amphibians Inhabiting a Constructed Wetland on the Savannah River Site

Proceedings of the 2011 Georgia Water Resources Conference, April 11, 12, and 13, 2011, Athens, Georgia.An artificial wetland system (H-02) was constructed on the Savannah River Site (SRS), South Carolina, to treat process and storm water discharge from an industrial facility. The ability of natural wetlands to improve many aspects of water quality is well known. One aspect of natural wetland function that is capitalized on at the H-02 wetlands is the ability to sequester trace metals such as copper (Cu) and zinc (Zn) from the effluent discharged into this wetland system. Constructed wetlands can provide new habitat for local wildlife, but if poor water quality limits recruitment, these wetlands could become “population sinks.” The H-02 wetlands provide permanent water that doesn’t have any fish, potentially providing ideal habitat for amphibians. However, amphibians are also highly susceptible to environmental contaminants. Thus, the potential for the constructed wetlands to become population sinks is of concern. We have been monitoring amphibian colonization of the H-02 wetlands and evaluating the effects of elevated levels of trace metals on amphibian success. Amphibians are ideally suited for studying the effects of contaminants because they are important components of aquatic and terrestrial communities and represent a large proportion of the standing biomass in some systems. In many communities amphibians are the most abundant vertebrates. Because of their high biomass and conversion efficiencies, they are responsible for substantial transfer of energy through food webs, and may also serve as a critical link in trophic transfer of contaminants. Consequently, if environmental contaminants negatively affect amphibian populations then the whole ecosystem can be impacted. A majority of studies examining the effects of contaminants on amphibians focus on acute toxicity studies of model organisms. Although these studies have contributed to the field of amphibian ecotoxicology they lack applicability to natural settings. Most toxicology studies only expose amphibians for the first 96 hours to two weeks of development. This approach is not biologically representative since most amphibians will be exposed for their entire larval development. In addition, different species develop at substantially different rates such that a two-week time period covers different ontogenetic exposure periods for different species. To truly understand the effects of contaminant exposure on amphibians it is important to expose them for the entire larval period and then assess the effects across multiple life stages. Amphibian species may differ in their sensitivities to contaminants, so it is also important to examine effects across a range of native species. The model organism typically studied is the African clawed frog, Xenopus laevis. Xenopus is unlike most amphibians in that it is entirely aquatic and it is also phylogenetically very distinct from most. Thirteen species of amphibians have colonized the H- 02 wetland complex since its construction. Those species differ in their feeding habits and larval duration. To incorporate these species differences we examined the effects of Cu exposure on three species of amphibians: southern leopard frogs (Rana sphenocephala), southern toads (Bufo terrestris), and eastern narrowmouthed toads (Gastrophryne carolinensis). For all three species we used an exposure period that extends from fertilization to metamorphosis. We conducted all studies in both a controlled laboratory setting with precise biologically relevant Cu treatments and in the wetlands where larvae were exposed to a water chemistry gradient under ambient field conditions. The H-02 treatment complex consists of a retention pond, which receives the process water, and two constructed wetland cells. Water in the retention pond has the highest levels of Cu, Zn, and pH, and after a residence time of several days water exiting the wetland cells has lower levels of these variables. For field studies we reared amphibians in the retention pond, and at both the influent and effluent ends of the treatment cells. We observed substantial species-level variation in sensitivity to contaminants at both the egg and larval stages. To accurately assess the impacts of contaminants on pond-breeding amphibians it is necessary to study native species throughout their aquatic life stages.Sponsored by: Georgia Environmental Protection Division U.S. Geological Survey, Georgia Water Science Center U.S. Department of Agriculture, Natural Resources Conservation Service Georgia Institute of Technology, Georgia Water Resources Institute The University of Georgia, Water Resources FacultyThis book was published by Warnell School of Forestry and Natural Resources, The University of Georgia, Athens, Georgia 30602-2152. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-307) or the other conference sponsors

Genotype data

Microsatellite genotype calls for all genotyped individuals from Archbold Biological Station including hatchlings and eggs from clutches examined in this study

Hatchling phenotypic data

Phenotypic data for all viable hatchlings collected for this study. Carapace and plastron measurements (in mm) and mass was measured for both the 2015 and 2016 cohort. Locomotor performance data on a 1m track was measured for the 2016 cohort only. Locomotor data (latency time, total time, initial speed, average speed, and max speed) is averaged across trials for each individual

Habitat use by female desert tortoises suggests tradeoffs between resource use and risk avoidance

Animals may select habitat to maximize the benefits of foraging on growth and reproduction, while balancing competing factors like the risk of predation or mortality from other sources. Variation in the distribution of food resources may lead animals to forage at times or in places that carry greater predation risk, with individuals in poor quality habitats expected to take greater risks while foraging. We studied Mojave desert tortoises (Gopherus agassizii) in habitats with variable forage availability to determine if risk aversion in their selection of habitat relative was related to abundance of forage. As a measure of risk, we examined tortoise surface activity and mortality. We also compared tortoise body size and body condition between habitats with ample forage plants and those with less forage plants. Tortoises from low forage habitats selected areas where more annual plants were nutritious herbaceous flowering plants but did not favor areas of greater perennial shrub cover that could shelter them or their burrows. In contrast, tortoises occupying high forage habitats showed no preference for forage characteristics, but used burrows associated with more abundant and larger perennial shrubs. Tortoises in high forage habitats were larger and active above ground more often but did not have better body condition. Mortality was four times higher for females occupying low forage habitat than those in high forage habitat. Our results are consistent with the idea that tortoises may minimize mortality risk where food resources are high, but may accept some tradeoff of greater mortality risk in order to forage optimally when food resources are limiting

Dietary Selenomethionine Administration and Its Effects on the American Alligator (Alligator mississippiensis): Oxidative Status and Corticosterone Levels

Selenium (Se) is an essential nutrient which in excess causes toxicity. The disposal of incompletely combusted coal, which often is rich in Se, into aquatic settling basins is increasing the risk of Se exposure worldwide. However, very few studies have looked at the physiological effects of Se exposure on long-lived, top trophic vertebrates, such as the American alligator (Alligator mississippiensis). During a 7-week period, alligators were fed one of three dietary treatments: mice injected with deionized water or mice injected with water containing 1000 or 2000 ppm selenomethionine (SeMet). One week after the last feeding alligators were bled within 3 min of capture for plasma corticosterone (CORT). A few days later, all alligators were euthanized and whole blood and tail tissue were harvested to measure oxidative damage, an antioxidant-associated transcription factor, and antioxidant enzymes [glutathione peroxidase-1 (GPX1), superoxide dismutase-1 (SOD1), and SOD2] by Western blotting. There was a dose-dependent increase in baseline CORT levels in alligators administered SeMet. Except for blood SOD2 levels, SeMet treatment had no effect (p \u3e 0.05 for all) on oxidative status: oxidative damage, GPX1, SOD1, and muscle SOD2 levels were similar among treatments. Our results illustrate that high levels of Se may act as a stressor to crocodilians. Future studies should investigate further the physiological effects of Se accumulation in long-lived, top-trophic vertebrates