Description of the tadpole of Leptodactylus syphax, with a comparison of morphological and ecological characters of tadpoles and adults of the species in the L-pentadactylus group (Leptodactylidae, Anura)

Leptodactylus syphax belongs to the L. pentadactylus group, one of five species groups defined for the genus. The tadpole of L. syphax develops in lotic habitats, as do the tadpoles of L. lithonaetes and L. rugosus. The tadpole of L. syphax is here described and differs from the tadpole of L. rugosus by having a less flattened and larger body, from the tadpole of L. lithonaetes by having a larger body in relation to total length and a larger oral disc in relation to body length. Further, it differs from the tadpole of L. rhodomystax by its color, body shape in dorsal profile and mouth shape, and from the tadpole of L. rhodonotus by its body shape in dorsal profile and spiracle position. A cluster analysis of several morphological and ecological features of adults and tadpoles from the species of the L. pentadactylus group grouped L. syphax with L. rhodomystax and L. rhodonotus, species with chest spines, moderate body size, relatively small head, unbarred lips, tadpoles with five tooth rows and aquatic development. The remaining species of the L. pentadactylus group were distributed among four additional clusters.