Mining a museum frog collection for environmental bio-indicators using specimens of the Striped Marsh Frog Limnodynastes peronii

Abstract

Museum specimens of the Striped Marsh Frog, (Limnodynastes peronii; Myobatrachidae), were examined to evaluateits potential role in providing bio-indicators of environmental quality and change. I hypothesized that chemical pollutionof their breeding habitat would have peaked during the 1960s or 1970s, and that the levels of physical abnormality and morphological asymmetry for this frog species would tend to increase with increasing pollution. Consistent with this, I found that both the proportion of frogs with physical abnormalities and the average difference in length between the left and right lower legs peaked for specimens collected during the 1960s or 1970s and were lower for specimens collected during earlier and later decades. I also found that the overall proportion of specimens of this species with physical abnormalities was high relative to presumed background levels, which is consistent with relatively elevated levels of pollution in the degraded habitats where this species generally occurs. In this and similar ways, biological collections may be mined to provide environmental bio-indicators.