“…In this experiment, we exposed juvenile frogs to a low concentration of Bd zoospores relative to most other investigators (Rachowicz et al, 2006;Retallick and Miera, 2007;Woodhams et al, 2007a). However, the concentration of zoospores we used was higher than that estimated from pond water in nature (Kirshtein et al, 2007;Walker et al, 2007). For example, Kirshtein et al, 2007 andWalker et al, 2007 estimated that zoospore density in ponds varied from 0.5 to 454 zoospores per liter, whereas our exposure protocol was 20 000 zoospores per liter for 24 h. A sampling of recent experimental papers reveals that individual amphibians were exposed to Bd densities in their experimental containers that ranged from 25 000 zoospores per liter (Rachowicz and Vredenburg, 2004) to 10 5 -10 6 zoospores per liter (Rachowicz et al, 2006;Retallick and Miera, 2007;Woodhams et al, 2007a).…”