In 2019, two wild-caught adult female eastern hellbenders () received a preshipment examination and were individually swabbed for chytrid testing via quantitative polymerase chain reaction (qPCR). Physical examination was unremarkable. Both females tested positive for () and negative for (). A course of terbinafine hydrochloride 1% in alcohol was administered in a 0.005% treatment bath for 5 min once daily for 5 d. Both animals were individually retested 1, 3, and 4 wk after treatment using qPCR. All post-treatment samples were negative for and . This report represents the first successful treatment with terbinafine hydrochloride 1% in alcohol to eliminate subclinical infection in eastern hellbenders and underlines the importance of preshipment testing for chytrid in all amphibians being transferred to new facilities or released into the wild as a means to minimize risk of disease introduction via subclinically infected individuals.
The eastern hellbender salamander is endangered and suffers from chytridiomycosis, a fungal disease primarily caused by Batrachochytrium dendrobatidis (Bd), leading to symptoms like skin shedding and death.
At Purdue University, 33% of hellbenders experienced mortality; autopsies revealed chytridiomycosis and a co-infection with Aeromonas hydrophila.
The outbreak was attributed to environmental stress from filtration failure; after treatment, surviving salamanders have remained healthy for over a year and were released back into the wild.
AbstractVector-borne blood parasites cause myriad sublethal effects and can even be deadly to endotherms, but far less is known about their impacts on ectothermic hosts. Moreover, the pathologies documented in endotherms are generally linked to infection by blood parasites rather than by their vectors. Here, we measured hematocrit, hemoglobin, and relative proportions of immature red blood cells to evaluate the physiological effects of two blood-feeding parasites and coinfection on ectothermic hosts, differentiating among pathological responses, extrinsic factors, and natural variations.
The behavioral endocrinology associated with reproduction and uniparental male care has been studied in teleosts, but little is known about hormonal correlates of uniparental male care in other ectotherms. To address this gap, we are the first to document the seasonal steroid endocrinology of uniparental male hellbender salamanders during the transition from pre-breeding to nest initiation, and through the subsequent eight months of paternal care. In doing so, we investigated the correlates of nest fate and clutch size, exploring hellbenders' alignment with several endocrinological patterns observed in uniparental male fish.
Detecting declines and quantifying extinction risk of long-lived, highly fecund vertebrates, including fishes, reptiles, and amphibians, can be challenging. In addition to the false notion that large clutches always buffer against population declines, the imperiled status of long-lived species can often be masked by extinction debt, wherein adults persist on the landscape for several years after populations cease to be viable. Here we develop a demographic model for the eastern hellbender (Cryptobranchus alleganiensis), an imperiled aquatic salamander with paternal care.
