Heterixalus

Abstract: Treefrogs of the family Hyperoliidae are distributed in Africa, Madagascar and the Seychelles. In this study, their phylogeny was studied using sequences of fragments of the mitochondrial 16Sand 12SrRNA and cytochrome b genes. The molecular data strongly confirmed monophyly of the subfamily Hyperoliinae but indicated that the genus Leptopelis (subfamily Leptopelinae) is more closely related to species of the African family Astylosternidae. The Seychellean genus Tachycnemis was the sister group of the Malagasy Heterixalus in all molecular analyses; this clade was deeply nested within the Hyperoliinae. A re-evaluation of the morphological data did not contradict the sister group relationships of these two genera. The subfamily Tachycneminae is therefore considered as junior synonym of the Hyperoliinae. In addition, the molecular analysis did not reveal justification for a subfamily Kassininae. Biogeographically, the origin of Malagasy hyperoliids may not be well explained by Mesozoic vicariance in the context of Gondwana breakup, as indicated by the low differentiation of Malagasy hyperoliids to their African and Seychellean relatives and by analysis of current distribution patterns.

Abstract: Males of all reed frog species (Anura: Hyperoliidae) have a prominent, often colourful, gular patch on their vocal sac, which is particularly conspicuous once the vocal sac is inflated. Although the presence, shape, and form of the gular patch are well-known diagnostic characters for these frogs, its function remains unknown. By integrating biochemical and histological methods, we found strong evidence that the gular patch is a gland producing volatile compounds, which might be emitted while calling. Volatile compounds were confirmed by gas chromatography-mass spectrometry in the gular glands in 11 species of the hyperoliid genera Afrixalus, Heterixalus, Hyperolius, and Phlyctimantis. Comparing the gular gland contents of 17 specimens of four sympatric Hyperolius species yielded a large variety of 65 compounds in species-specific combinations. We suggest that reed frogs might use a complex combination of at least acoustic and chemical signals in species recognition and mate choice.(c) 2013 The Authors. Biological Journal of the Linnean Society published by John Wiley & Sons Ltd on behalf of The Linnean Society of London. (Less)