Description of the tadpole of Leptodactylus vastus (Anura: Leptodactylidae)

The Neotropical frog Leptodactylus vastus belongs to the L. pentadactylus group, a group that currently contains 14 species, and of which nine tadpoles have been described. The tadpoles of L. vastus described here are generally much smaller than tadpoles of the other species described. The oral disk of L. vastus tadpoles is almost anteriorly placed, similar to other tadpoles in the group except for L. lithonaetes and L. rugosus, and the rows of marginal papillae in L. vastus are different from those in the other species. The tadpoles of L. vastus have a 1/2(1) LTRF similar to that of L. labyrinthicus and amazonian L. pentadactylus, whereas other species in the group show different arrangements of the tooth rows. The internal oral characteristics of the tadpole of L. vastus differs from L. knudseni and L. pentadactylus by having four infralabial papillae, possess 4–5 prepocket papillae surrounded by postulations and the buccal roof arena is circular, surrounded by two long papillae and 4–6 smaller papillae. The tadpoles of L. vastus, in general, possess a set of morphological characteristics that are very similar to those of other species of the L. pentadactylus group, and some of them are probably related to tadpole ecology.