Variation and systematics of frogs of the Genus Cycloramphus (Amphibia, Leptodactylidae)

Abstract

Variation is analyzed among members of the Neotropical frog genus Cycloramphus. The results of the analyses of variation are used in part to delimit species. Twenty one species are recognized, nine of them are described as new. The genus Craspedoglossa is considered a synonym of Cycloramphus. The genus Scythrophrys is not closely related to Cycloramphus, but the genus Zachaenus is. A definition for the genus Cycloramphus is provided, as are taxonomic summaries for each species. The species accounts include a skeletal synonymy, diagnosis of adults, a morphological definition of adults and larvae where known, an advertising call description and a distributional summary with localities and maps. A detailed description of the holotype is provided for each new species. A key to the species distinguishes adult specimens of Cycloramphus. Much of the interspecific variation is of about the same magnitude as intraspecific variation. Natural selection has resulted in changes of both size and shape among species of the genus Cycloramphus. There are no universal patterns of species differentiation and sympatric occurrence. The kinds and degrees of differences among species appear to be geographically specific.