The corroboree frog: going, going...

[kyle1745]

The recent decline of frogs worldwide is now well established but the causes of this decline remain unclear. Australia has a highly diverse and species-rich frog fauna and a number of species have declined significantly over the last 30 years. Two iconic species in particular have been the subject of considerable concern because their decline has been so rapid and extreme. The northern corroboree frog, Pseudophryne pengilleyi, and the southern corroboree frog, Pseudophryne corroboree, are small, pond-breeding and very brightly coloured terrestrial frogs restricted parts of the alpine and subalpine regions of the southern highlands of New South Wales and the Australian Capital Territory in Australia. The rapid decline of both species of corroboree frog is noteworthy because it has been so well documented. In response to the continued decline and critically low population size, a captive husbandry programme has commenced. This recovery action currently includes (i) collection of eggs from the wild each summer with captive rearing of tadpoles through to metamorphosis and subsequent re-introduction of frogs to the wild, and (ii) establishment of a captive breeding colony for producing frogs for re-introduction. An understanding of the magnitude and patterns of genetic diversity among populations is critical for conservation efforts attempting to maintain evolutionarily viable species.

Assessment of genetic diversity in the critically endangered Australian corroboree frogs, Pseudophryne corroboree and Pseudophryne pengilleyi, identifies four evolutionarily significant units for conservation. Molecular Ecology, 20 Jun 2008
The iconic and brightly coloured Australian northern corroboree frog, Pseudophryne pengilleyi, and the southern corroboree frog, Pseudophryne corroboree are critically endangered and may be extinct in the wild within 3 years. We have assembled samples that cover the current range of both species and applied hypervariable microsatellite markers and mitochondrial DNA sequences to assess the levels and patterns of genetic variation. Bayesian clustering analyses in structure strongly supported four genetically distinct populations, which correspond exactly to the four main allopatric geographical regions in which the frogs are currently found. Individual analyses performed on the separate regions showed that breeding sites within these four regions could not be separated into distinct populations. A statistical parsimony network of mtDNA haplotypes shows two distinct groups, which correspond to the two species of corroboree frog, but with most of the haplotype diversity distributed in P. pengilleyi. These results demonstrate an unexpectedly high level of genetic diversity in both species. Our data have important implications for how the genetic diversity is managed in the future. The four evolutionarily significant units must be protected and maintained in captive breeding programmes for as long as it is possible to do.

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