Extremely Low Prevalence of Batrachochytrium dendrobatidis Infection in Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis) in Southwest Virginia, USA

摘要

The large, fully aquatic Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) is a phylogenetically unique member of North America's salamander diversity and a focus of increasing conservation concern. Substantial population declines have been reported across much of the Eastern Hellbender's range (Wheeler et al. 2003; Foster et al. 2009; Burgmeier et al. 2011b), and this subspecies is now apparently extirpated from some historical localities (Graham et al. 2011). Exact causes for population declines are unclear, although habitat degradation is often suspected to play a significant role (Wheeler et al. 2003; Foster et al. 2009; Graham et al. 2011). Recently, however, studies have documented Batrachochytrium dendrobatidis (Bd) infection in both captive and wild hellbender populations (Briggler et al. 2007; Briggler et al. 2008; Gonynor et al. 2011; Bodinof et al. 2012; Regester et al. 2012; Tominaga et al. 2013). This fungal pathogen has been detected on hellbender museum specimens collected as far back as 1969 (Bodinof et al. 2011). Bd causes the devastating amphibian disease chytridiomycosis (Berger et al. 1998; Kilpatrick et al. 2010; Eskew and Todd 2013), and evidence from the tropics suggests that disease-driven amphibian declines may have wide-ranging effects on ecosystem functioning in lotic systems (Whiles et al. 2006). However, the prevalence of Bd in river-and stream-associated amphibians from temperate latitudes is understudied; the limited data currently available suggests that Bd infection is at relatively low prevalence in low-order stream systems in the US (Hossack et al. 2010).