The microanatomy of the oral disc and the buccal cavity of the tadpole of Leptodactylus labyrinthicus is described and compared with other species included in the L. pentadactylus species group. Thirty-five tadpoles between stages 25 and 46 had been dissected and analyzed in scanning electron microscopy. The oral and internal buccal morphology was analyzed in tadpoles between stages 36 and 39. The buccal morphology of the tadpole of L. labyrinthicus is similar to other tadpoles with adaptation to macrophagy, such as the strong queratinization of the jaw, reduction of the internal buccal structures and presence of one glote uncovered, propitious to carnivorous diets. The tadpole of L. pentadactylus species group share this trend to the reduction of the structures of selection and capture of particle, including reduction in the number of the buccal roof and floor arena papillae, reduction or absence of anterior papillae on the buccal pocket, only two postnarial papillae, small lateral ridge papillae and glandular zones restricted in narrow bands on the edge of velum. In the tadpoles of genera Leptodactylus the larval morphology reflects the current groups considered for this genera.
internal oral morphology; macrophagy; carnivory; Leptodactylus pentadactylus group
