DAO 107:69-75 (2013)  -  DOI: https://doi.org/10.3354/dao02669

ABSTRACT: Chytridiomycosis is an emerging disease that has driven some amphibian species to extinction while leaving others apparently unharmed. Its causative agent, Batrachochytrium dendrobatidis (Bd), now persists endemically in many amphibian communities. Understanding host species response to Bd infection is critical for managing chytridiomycosis because the epidemiology of this disease is host-specific. Dendropsophus meridensis is an endangered hylid frog endemic to the Venezuelan Andes. This species is sympatric with the American bullfrog Lithobates catesbeianus, an introduced species known to act as a reservoir for Bd. High prevalence of infection and high zoospore burdens in wild populations of D. meridensis in the Venezuelan Andes suggested some tolerance for Bd. However, experimental exposure of post-metamorphic frogs resulted in 53% mortality, a value that represents a 14-fold increase in the odds of dying compared to control frogs. Repeated diagnostics using real-time polymerase chain reaction assays demonstrated that individuals that died accumulated a higher number of zoospores than those that survived, although this value was lower than the mean zoospore burdens observed in natural populations. Given the susceptibility of D. meridensis to a strain of Bd isolated from a nearby population of bullfrogs, we emphasize the need to limit the dispersion of this invasive species.

KEY WORDS: Amphibians · Chytrid fungus · Chytridiomycosis · American bullfrogs · Experimental infections · Venezuela