Friday, 26 September 2008
Captive Breeding Introduced Bd To Mallorcan Midwife Toads
The Mallorcan midwife toad, Alytes muletensis, is one of the worlds most highly endangered amphibian species. Presumed extinct until 1978, the species was 're-discovered' hiding in the arid Sierra de Tramuntana mountains in the north of the Island; the species has subsequently been the focus of a highly successful captive-breeding and reintroduction program. However, mortalities and subsequent detection of high-prevalence infection by Bd clustered into two adjacent breeding-sites rang alarm-bells. Subsequent investigations, reported by Walker et al in Current Biology showed that introduced Alytes were infected by Bd as early as 1989, and had likely picked up the infection in captivity. The paper reports the first use of sequence-typing to demonstrate that island genotypes of Bd are identical, and unrelated to others found in Europe, strengthening the hypothesis that a single introduction of Bd had occurred. The paper reinforces the need for stringent biosecurity methods to prevent cross-transmission of known and unknown pathogens in captivity. As Kevin Zippel of AArk states "It's a much-needed wake-up call. We must do everything in our power to assess and minimize the risks."