A lizard acting as carrier of the amphibian-killing chytrid Batrachochytrium dendrobatidis in southern Brazil

Abstract

Fungal infections are causing widespread population declines and extinctions in all vertebrate classes. Among them, an important fungal disease chytridiomycosis, caused by the pathogenic chytrid Batrachochytrium dendrobatidis (Bd). With an aquatic infectious phase, Bd does not survive desiccation for long, but may be transported by non-amphibian carriers. Such mechanism is key to understand amphibian-chytrid dynamics and may contribute to local amphibian conservation action plans. Therefore, we surveyed Bd in reptiles from two different Brazilian rainforests, looking for possible Bd carriers. We sampled 35 individuals belonging to 11 squamate families, five from the Atlantic Forest and 30 from the Amazon. We detected Bd in one adult lizard, Placosoma glabellum. This lizard feeds, shelters, and breeds in the leaf-litter, and moves between Atlantic Forest streams. Hence, it may be carrying Bd from stream to stream, and also spreading the pathogen to direct-developing amphibians, which have no contact with water bodies and are more susceptible to chytridiomycosis than aquatic species. This is the first record of a non-amphibian chytrid carrier in South America. We suggest that additional field and museum samplings will contribute to understand whether Bd can actually infect reptiles, and how reptile carriers can affect chytrid dynamics in the wild.