Influence of Water Speed on Tadpoles of Ranidella signifera and R. riparia (Anura:Leptodactylidae)

Abstract

Ranidella riparia is restricted to the Flinders Ranges of South Australia. and has a distribution largely allopatric to that of the morphologically similar species, R. signifera. The distributions of these two species overlap in the lower Flinders Ranges. In an experimental water flow, tadpoles of R. riparia were less often moved by the water current than those of R. signifera, and the difference increased with increasing water speed. In the Flinders Ranges most of the breeding habitat for frogs is in fast flowing creeks. The likelihood that tadpoles of R. signifera would be swept away in these creeks may be a factor restricting its distribution in this area.