Bioaccoustics And Morphology Of The Ridged Frog Species, Ptychadena (Amphibia: Ranidae), From Kakamega Forest, Western Kenya

Abstract

The genus Ptychadena belongs to the family of "true fogs" Ranidae. This Family has a world-wide distribution (except in Australia and New Zealand) with 746 species in 44 genera. Ptychadena occurs in Sub-Saharan Africa and along the Nile into Egypt; some species were introduced to Madagascar, the Seychelles, and Mascarene Islands. The taxonomy of the genus is controversial, and the position of certain taxa is still questionable. In the present study, morphology, morphometries and bioacoustics were used to review Ptychadena species occurring in the Kakamega Forest in Western Kenya. A total of 134 specimens were collected for the study and out of these, calls were recorded from 11 individuals. Using STATISTICA, Principle component analyses (PCA) was performed on the morphometries and qualitative characters were used to compare the similarities between the species studied. Calls were digitized and call properties measured using computer software Cool edit. The results from morphometric characters alone were not informative enough suggesting that measurements alone are not good characters in the taxonomic study of Ptychadena species. Non- morphometric characters on the other hand proved to be informative in identification as they presented a trend suggesting the presence of five species. However, when the two techniques (morphometries and non-morphometric) were used together, it was possible to isolate two species these are. Ptychadena tellinii (Peracca, 1904) and P. anchietae (Bocage, 1867). The combined analysis, however, could not separate P. porosissima (Steindachner, 1854), P. mascareniensis (Dumeril and Bibron, 1841) and P. . taenioscelis (Laurent, 1954) from each other. Bioacoustics analysis also confirmed the presence of three Ptychadena species in Kakamega Forest these are, P. tellinii and further split P. mascareniensis and P. porosissima from the complex resulting from the combined analysis above. The results presented in. this study support the use of combined analysis

(morphometric and non-morphometric characters) and bioacoustics III the study of the Ptychadena of Kakamega Forest.