The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform

Rod N Williams - One of the best experts on this subject based on the ideXlab platform.

  • movement and habitat use of eastern hellbenders Cryptobranchus alleganiensis alleganiensis following population augmentation
    Herpetologica, 2018
    Co-Authors: Emily B Mccallen, Bart T Kraus, Nick G Burgmeier, Songlin Fei, Rod N Williams
    Abstract:

    Abstract With amphibian declines at crisis levels, translocations, including population augmentations, are commonly used for amphibian conservation. Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis) have declined to low densities in many areas of their range, making them ideal candidates for population augmentation. Both wild adults and captive-reared juveniles have been used for augmentations, but their suitability has never been directly compared. Herein, we use radio telemetry with Eastern Hellbenders to examine patterns of site fidelity, movement, and habitat use over a 2-yr period for adult residents, wild adult translocates, and captive-reared juvenile translocates. We used generalized linear models and generalized linear mixed models to identify temporal trends and explore the effects of residential status (resident vs. translocate) and origin/age (captive-reared juveniles vs. wild adults) on various ecological and behavioral traits relating to habitat. Site fidelity was high in adul...

  • Genetic confirmation of filial cannibalism in North America’s giant salamander, the Eastern hellbender Cryptobranchus alleganiensis alleganiensis
    2017
    Co-Authors: Shem D. Unger, Rod N Williams
    Abstract:

    Genetic confirmation of filial cannibalism in North America’s giant salamander, the Eastern hellbender Cryptobranchus alleganiensis alleganiensis

  • Evaluating the Survival of Translocated Adult and Captive-reared, Juvenile Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis)
    Herpetologica, 2017
    Co-Authors: Bart T Kraus, Emily B Mccallen, Rod N Williams
    Abstract:

    Abstract Recent amphibian declines have been addressed with a variety of conservation tools, including translocations. It is important to evaluate the success of ongoing amphibian conservation programs. In Indiana, USA, because of the documented decline of the Eastern Hellbender (Cryptobranchus a. alleganiensis) population, translocations of wild-captured and captive-reared individuals have been implemented as a management strategy. Our study was developed to estimate the annual survivorship of translocated versus resident Eastern Hellbenders and to compare the efficacy of translocating wild adults and captive-reared juveniles. Adult residents, and translocated adult and juvenile subjects, were implanted with radio transmitters in a staggered entry design and tracked for up to 2 yr. A Cox proportional hazards model indicated that captive-reared, juvenile hellbenders had lower annual survival rates than did either resident or translocated adults. The relatively high survival rates of all groups indicated t...

  • Characterization of the Cutaneous Bacterial Communities of Two Giant Salamander Subspecies
    Microbial Ecology, 2016
    Co-Authors: Obed Hernández-gómez, Steven J. A. Kimble, Jeffrey T. Briggler, Rod N Williams
    Abstract:

    Pathogens currently threaten the existence of many amphibian species. In efforts to combat global declines, researchers have characterized the amphibian cutaneous microbiome as a resource for disease management. Characterization of microbial communities has become useful in studying the links between organismal health and the host microbiome. Hellbender salamanders (Cryptobranchus alleganiensis) provide an ideal system to explore the cutaneous microbiome as this species requires extensive conservation management across its range. In addition, the Ozark hellbender subspecies (Cryptobranchus alleganiensis bishopi) exhibits chronic wounds hypothesized to be caused by bacterial infections, whereas the eastern hellbender (Cryptobranchus alleganiensis alleganiensis) does not. We assessed the cutaneous bacterial microbiome of both subspecies at two locations in the state of Missouri, USA. Through 16S rRNA gene-based amplicon sequencing, we detected more than 1000 distinct operational taxonomic units (OTUs) in the cutaneous and environmental bacterial microbiome. Phylogenetic and abundance-based dissimilarity matrices identified differences in the bacterial communities between the two subspecies, but only the abundance-based dissimilarity matrix identified differences between wounds and healthy skin on Ozark hellbenders. The higher abundance of OTUs on Ozark wounds suggests that commensal bacteria present on the skin and environment may be opportunistically colonizing the wounds. This brief exploration of the hellbender cutaneous bacterial microbiome provides foundational support for future studies seeking to understand the hellbender cutaneous bacterial microbiome and the role of the bacterial microbiota on chronic wounds of Ozark hellbenders.

  • Conserving the Eastern Hellbender Salamander
    Human Dimensions of Wildlife, 2014
    Co-Authors: Nathan Mullendore, Rod N Williams, Amber Saylor Mase, Kate K. Mulvaney, Rebecca Perry-hill, Adam Reimer, Lamis Behbehani, Linda Stalker Prokopy
    Abstract:

    Through a mail survey of 541 residents and riparian landowners in the area surrounding the Blue River watershed of southern Indiana, we examined perceptions and intended behaviors toward the eastern hellbender (Cryptobranchus alleganiensis alleganiensis), an aquatic salamander experiencing drastic population declines due to anthropogenic causes. While anecdotal reports attribute hellbender mortality and removal to anglers and pet collectors, only 5% of respondents reported these negative behaviors. Misconceptions among anglers and the general public about the eastern hellbender were less prevalent than anticipated. Anglers, recreational boaters, riparian landowners, and respondents who were previously familiar with the hellbender displayed more positive attitudes toward the animal than other groupings of individuals. Data collected in this article shaped a detailed education and outreach campaign based on the principles of community-based social marketing.

William A. Hopkins - One of the best experts on this subject based on the ideXlab platform.

  • Haematological and immunological characteristics of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) infected and co-infected with endo- and ectoparasites.
    Conservation physiology, 2016
    Co-Authors: William A. Hopkins, Jesse A. Fallon, Michelle L. Beck, Brittney H. Coe, Catherine M. Bodinof Jachowski
    Abstract:

    Disease is among the leading causes of the global decline in amphibian populations. In North America, parasites and pathogens are among the factors implicated in precipitous population declines of the giant hellbender salamander (Cryptobranchus alleganiensis), but the incidence of infections and the responses of hellbenders to infections remain poorly studied. Here, we document the prevalence of leech and trypanosome infections in a wild population of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) and describe haematological and immunological characteristics of hellbenders harbouring these infections. We hypothesized that hellbenders parasitized by trypanosomes would be anaemic, that individuals infected with either or both parasites would exhibit shifts in white blood cell counts and that hellbenders infected with leeches would exhibit altered plasma bactericidal capacity. We found that 24 and 68% of hellbenders in our sample population were infected with leeches and trypanosomes, respectively, and 20% were co-infected with both parasites. We found no evidence suggestive of anaemia among infected individuals. However, hellbenders infected with either or both parasites exhibited marked shifts in circulating white blood cells that were consistent with predictable responses to parasitic infection. Additionally, we found that hellbenders harbouring leeches had much higher plasma bactericidal capacity than individuals without leeches, and we offer multiple potential mechanistic explanations for this observation. We also found evidence that cellular and serological immune responses to parasites were less robust in juvenile than adult hellbenders. This finding warrants further investigation in light of the demographic characteristics, specifically the scarcity of juvenile age classes, of hellbender populations where disease is a possible contributor to declines. Finally, we describe two methodological advances that will improve future studies seeking to diagnose trypanosome infections and to test the bactericidal capacity of hellbenders and perhaps other amphibians. Our study provides fundamental insights into how hellbenders respond physiologically to endo- and ectoparasites, which could ultimately prove useful for their conservation.

  • Redescription of Placobdella cryptobranchii 1 Redescription and molecular characterization of Placobdella cryptobranchii (Johnson &
    2016
    Co-Authors: William E. Moser, Jeffrey T. Briggler, William A. Hopkins, Chawna D. Schuette, Dennis J. Richardson, Charlotte I. Hammond, Eric A. Lazo-wasem
    Abstract:

    Placobdella cryptobranchii (Johnson & Klemm, 1977) was originally described from specimens collected from Ozark Hellbenders (Cryptobranchus alleganiensis bishopi) from the North Fork of the White River i

  • Redescription and molecular characterization of Placobdella cryptobranchii (Johnson & Klemm, 1977) (Glossiphoniidae, Hirudinida).
    ZooKeys, 2013
    Co-Authors: Bill Moser, Jeffrey T. Briggler, William A. Hopkins, Chawna D. Schuette, Dennis J. Richardson, Charlotte I. Hammond, Eric A. Lazo-wasem
    Abstract:

    Placobdella cryptobranchii (Johnson & Klemm, 1977) was originally described from specimens collected from Ozark Hellbenders (Cryptobranchus alleganiensis bishopi) from the North Fork of the White River in Missouri, U.S.A. Leeches collected during August 2009 to August 2011 from five localities in Missouri (including the type locality) facilitated a redescription and molecular characterization of Placobdella cryptobranchii. Placobdella cryptobranchii has a rusty, reddish-brown dorsum with 2 lateral rows of unpigmented papillae, two unpigmented nuchal bands, unpigmented patches, and pair of four pre-anal papillae. Molecular comparison of CO-I sequence data from Placobdella cryptobranchii revealed a 93–94% similarity to Placobdella ornata and 10–17% difference among other species of Placobdella.

  • Widespread trypanosome infections in a population of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) in Virginia, USA
    Parasitology research, 2012
    Co-Authors: Andrew K. Davis, William A. Hopkins
    Abstract:

    Eastern hellbender salamanders (Cryptobranchus alleganiensis alleganiensis) are declining in North America and because of this the health status of individuals in several populations is closely monitored by researchers. During a health survey of hellbenders from a stream in Smyth County, VA, USA, we examined Giemsa-stained blood smears of 71 animals captured during 2011 for the presence of blood parasites. We discovered an unknown species of trypanosome that was apparently widespread within this population; 40 of the 71 individuals (56.3 %) were infected. There are seven known trypanosome species of caudate amphibians; based on microscopic examination, the parasite we observed appeared most similar to Trypanosoma cryptobranchi, which was reported in this species only once before, 76 years ago, from a single animal apparently captured in Iowa. Given that some trypanosomes can adversely affect the health of their hosts, we recommend further monitoring be done in this and other hellbender populations to determine the geographic extent of the parasite and its effects on its increasingly rare host.

  • SHORT COMMUNICATION Widespread
    2012
    Co-Authors: Andrew K. Davis, William A. Hopkins
    Abstract:

    trypanosome infections in a population of eastern hellbenders (Cryptobranchus alleganiensi

Craig P. Paukert - One of the best experts on this subject based on the ideXlab platform.

Jacob T. Westhoff - One of the best experts on this subject based on the ideXlab platform.

Andrew K. Davis - One of the best experts on this subject based on the ideXlab platform.

  • Widespread trypanosome infections in a population of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) in Virginia, USA
    Parasitology research, 2012
    Co-Authors: Andrew K. Davis, William A. Hopkins
    Abstract:

    Eastern hellbender salamanders (Cryptobranchus alleganiensis alleganiensis) are declining in North America and because of this the health status of individuals in several populations is closely monitored by researchers. During a health survey of hellbenders from a stream in Smyth County, VA, USA, we examined Giemsa-stained blood smears of 71 animals captured during 2011 for the presence of blood parasites. We discovered an unknown species of trypanosome that was apparently widespread within this population; 40 of the 71 individuals (56.3 %) were infected. There are seven known trypanosome species of caudate amphibians; based on microscopic examination, the parasite we observed appeared most similar to Trypanosoma cryptobranchi, which was reported in this species only once before, 76 years ago, from a single animal apparently captured in Iowa. Given that some trypanosomes can adversely affect the health of their hosts, we recommend further monitoring be done in this and other hellbender populations to determine the geographic extent of the parasite and its effects on its increasingly rare host.

  • SHORT COMMUNICATION Widespread
    2012
    Co-Authors: Andrew K. Davis, William A. Hopkins
    Abstract:

    trypanosome infections in a population of eastern hellbenders (Cryptobranchus alleganiensi