The Oral Cavities of Central European Anuran Larvae (Amphibia)

With few additions (structures here called prenarial lobes, prenarial arena pustulations, prevalar pustulations), WASSERSUG'S ( 1976) terminology is adequate to describe the oral structures of Central European anuran larvae. The oral cavities of Bombina and Alytes (Discoglossidoidei) are very similar in structure. Based on oral anatomy Pelabates fuscus appears to occupy an intermediate position within the Anura and a basal position among the Ranoidea, which are morphilogical very heterogeneous in oral characters. This assessment is consistent with the findings of other authors working on the anatomy of the tadpole head. Extensive morphological diversity can be found even within the genus Rana (Greenfrogs, Brownfrogs). It is, however, possible to clearly differentiate between genera and a generic key is presented based on the oral features. The oral ontogeny begins as soon as larval growth begins (stage 28). Lingual papillae, the buccal floor arena (BFA), the buccal pockets, the prenarial papillae and the median ridge papillae all differentiate very early. The anlagen for all larval structures are already present at stage 25.