Health and Habitat Quality Assessment for the Eastern Hellbender (Cryptobranchus Alleganiensis Alleganiensis) in Indiana, Usa

Abstract

ABSTRACT:The eastern hellbender (Cryptobranchus alleganiensis alleganiensis) has experienced precipitous population declines throughout its range. Numerous factors are speculated to be involved, but no empirical evidence has been presented for any. We implemented a populationwide health assessment in Indiana, USA, examining both the physical well-being of individuals and the quality of their habitat. Physicochemical parameters were analyzed directly in the field and later in the laboratory, when appropriate. Samples were collected June 2008-October 2008 and June 2009-September 2009 for reproductive analysis, blood screening, and disease prevalence. Of 27 chemicals screened in water samples, three were found in the study site, including atrazine. Atrazine was found at levels reported to cause reproductive problems in other amphibians. Vitellogenin was detected only in females and proved a reliable indicator of sex. Sperm parameters were generally of high quality and similar to other populations. Most plasma parameters were similar between sexes, although there were significant differences in calcium and potassium concentrations. Abnormalities were common, occurring in 68% of individuals. No hemoparasites were found, but amphibian chytrid fungus (Batrachochytrium dendrobatidis) was detected on one individual. Our findings establish a baseline for hematology and water-quality parameters that can be used as a model for evaluating population health throughout the hellbender range.

Movement and Habitat Use of Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis) Following Population Augmentation

“…Habitat use was similar at managed and unmanaged sites and between wild adult residents and translocates. Mean shelter rock size was comparable to, and the mean number of surrounding shelter rocks was slightly higher than, previous reports for this population (Burgmeier et al 2011b). Both shelter rock size and number of surrounding shelter rocks were comparable between wild translocates and residents.…”

“…The Blue River is an entrenched river bordered by a mosaic of agricultural fields and forest habitat. The substrate is largely gravel and cobble with sections of bare bedrock (Burgmeier et al 2011b), but there is substantial sedimentation within the system (personal observations). Like many rivers in which Eastern Hellbenders are found (Nickerson and Mays 1973), appropriate habitat consisting of dense groups of boulders is patchily distributed throughout the river.…”

“…In Indiana, Eastern Hellbenders are restricted to a single river with densities reduced by two orders of magnitude over a 25-yr period (Burgmeier et al 2011c). Although the original causes of decline are unclear (Burgmeier et al 2011b), current recruitment failure is likely exacerbated by limited mating opportunities attributable to the low population density. Individuals in the river are patchily distributed in fragments of suitable habitat, which often results in isolation (Burgmeier et al 2011c).…”

Seasonal variations in plasma vitellogenin and sex steroids in male and female Eastern Box Turtles, Terrapene carolina carolina

“…To determine reproductive condition of females and if there were endocrine disruptors in males, we screened both male and female plasma samples for the presence/absence of Vtg using a phosphoprotein gel stain assay [63] with modification as described in Burgmeier et al [4]. Plasma proteins (2 lg) were separated using 4% stacking/8% resolving sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under discontinuous conditions (tris-glycine buffer, pH 8.3) with 200 V (Mini-Protean III, Bio-Rad Laboratories, Inc., Hercules, California, USA).…”

“…For that reason, Vtg has also been used as a biomarker for noninvasive sexing of sexually monomorphic, ectothermic species [4] and may be useful in determining the sex of ambiguous adults. However, the synthesis of the Vtg protein can occur in males when exposed to exogenous estrogens and has been linked to environmental estrogenic endocrine disruption in fishes [18,22,47,56,61,65].…”