Absence of invasive Chytrid fungus (Batrachochytriumdendrobatidis) in native Fijian ground frog (Platymantisvitiana) populations on Viwa-Tailevu, Fiji Islands

Abstract

We report on the first survey of chytridiomycosis (Batrachochytrium dendrobatidis- Bd) in the endangered Fijian ground frog (Platymantis vitiana) population on Viwa-Tailevu, Fiji Islands. This fungal pathogen has been implicated as the primary cause of amphibian declines worldwide. Few cases have been reported from tropical Asia however it was recently documented in 4 species of frogs in Indonesia. Two hundred individual frogs were swabbed from 5 different sites on Viwa Island. Swabs were tested to quantify the number of Bd zoospore equivalents using real-time Polymerase Chain Reaction (qPCR) technique. We found zero (%) prevalence of Bd in ground frogs. The lack of Bd may be due to 1) hot weather all year round inhibiting the spread of Bd, 2) Bd may be absent from Viwa Island due to a lack of amphibian introductions (not introduced or importation of exotic frogs such as Rana catesbeiana, or Xenopus spp or pet trade spp) or 3) the lack of introduction by human vectors due to the geographic isolation, and low visitation of non-local people into the island. While it is difficult to test these hypotheses, a precautionary approach would suggest an effective quarantine is required to protect Fiji’s endemic frogs from future disease outbreak. Conservation effort and research is needed at international level to assist the Fiji government in monitoring and protecting their unique endemic amphibians from outbreaks of B. dendrobatidis.