From 1999 to 2006, we sampled >1200 amphibians for the fungal pathogen Batrachochytrium dendrobatidis (Bd) at 30 sites in the southeastern USA. Using histological techniques or PCR assays, we detected chytrid infection in 10 species of aquatic-breeding amphibians in 6 states. The prevalence of chytrid infection was 17.8% for samples of postmetamorphic amphibians examined using skin swab-PCR assays (n = 202 samples from 12 species at 4 sites). In this subset of samples, anurans had a much higher prevalence of infection than caudates (39.2% vs. 5.5%, respectively). Mean prevalence in ranid frogs was 40.7%. The only infected salamanders were Notophthalmus viridescens at 3 sites. We found infected amphibians from late winter through late spring and in 1 autumn sample. Although we encountered moribund or dead amphibians at 9 sites, most mortality events were not attributed to Bd. Chytridiomycosis was established as the probable cause of illness or death in fewer than 10 individuals. Our observations suggest a pattern of widespread and subclinical infections. However, because most of the sites in our study were visited only once, we cannot dismiss the possibility that chytridiomycosis is adversely affecting some populations. Furthermore, although there is no evidence of chytrid-associated declines in our region, the presence of this pathogen is cause for concern given global climate change and other stressors. Although presenceabsence surveys may still be needed for some taxa, such as bufonids, we recommend that future researchers focus on potential population-level effects at sites where Bd is now known to occur.

The presence in the southeastern USA of Batrachochytrium dendrobatidis, a fungal pathogen of amphibians, is a potential threat to the diverse salamander assemblages in the region. In this study, we tested the susceptibility of plethodontid salamanders to infection with B. dendrobatidis. We experimentally infected one terrestrial species (Plethodon metcalfi) and one stream-dwelling species (Desmognathus monticola). Mortality of P. metcalfi due to B. dendrobatidis infection was 41.7% and was higher at 8°C (75%) than at 16°C (8.3%). B. dendrobatidis did not cause any mortality in D. monticola. Infected salamanders exhibited few of the clinical signs associated with B. dendrobatidis infection; however, they exhibited histologic signs of disease. Our results suggest that Plethodon species in the southeastern USA are at risk of becoming infected with B. dendrobatidis and developing chytridiomycosis. However, some animals may have survived with or cleared the infection. Additional studies are required to determine whether chytridiomycosis is a significant factor in declines of plethodontid salamanders. KEY WORDS: Chytridiomycosis · Batrachochytrium dendrobatidis · Salamander · Amphibian · MortalityResale or republication not permitted without written consent of the publisher

Amphibian population declines are often associated with disease outbreaks at metamorphosis. We examine the ontogeny of innate immunity in a range of amphibians and find that skin peptide defenses may partially compensate for adaptive immune suppression during this sensitive stage. Skin defense trade-offs with development reflect amphibian life-history strategy.

A researcher at the authors' institution needed to house adult bullfrogs (Rana catesbeiana) individually. The authors responded to this need by modifying 5-gallon plastic buckets to use for individual housing of bullfrogs. These buckets provided a simple, inexpensive housing system that successfully maintained healthy and behaviorally normal frogs. The authors describe the housing and husbandry of the bullfrogs in this individual housing situation and recommend it for use by others.