Descriptions of the tadpoles of two species of Gephyromantis, with a discussion of the phylogenetic origin of direct development in mantellid frogs

We describe the larval stages of two Malagasy frog species of the genus Gephyromantis, based on specimens identified by DNA barcoding. The tadpoles of Gephyromantis ambohitra are generalized stream-living Orton type IV type larvae with two lateral small constrictions of the body wall at the plane of spiracle. Gephyromantis pseudoasper tadpoles are characterized by totally keratinised jaw sheaths with hypertrophied indentation, a reduced number of labial tooth rows, enlarged papillae on the oral disc, and a yellowish coloration of the tip of the tail in life. The morphology of the tadpole of G. pseudoasper agrees with that of G. corvus, supporting the current placement of these two species in a subgenus Phylacomantis, and suggesting that the larvae of G. pseudoasper may also have carnivorous habits as known in G. corvus. Identifying the tadpole of Gephyromantis ambohitra challenges current assumptions of the evolution of different developmental modes in Gephyromantis, since this species is thought to be related to G. asper, a species of supposedly endotrophic direct development