The basin white-lipped frog, Leptodactylus mystaceus, is a common South American leptodactylid frog that occurs widely across the Amazon basin from Columbia, Venezuela, the Guianas, and Surinam through eastern Ecuador, Peru and Bolivia, and across central Brazil. A rather large ground-dwelling frog, adult reach snout-vent lengths of 47-50 mm; females are slightly larger than males. This frog inhabits areas near standing water in a variety of habitats including rainforest, forest edge, and open areas (Heyer, R. and M.T. Rodrigues 2010; Heyer et al. 1996; Toledo et al. 2005).
The genus Leptodactylus contains more than 60 known species; L. mystaceus is one of 26 species placed in the L. fuscus group, the largest of the four morphologically-based groupings (Toledo et al. 2005).
Leptodactylus mystaceus can be difficult to distinguish from other frogs in the L. fuscus group, especially from closely related species L. didymus and L. notoakitites. Morphologically identical to L. mystaceus, L. didymus was only recognized as a separate (cryptic) species in 1996; its name (didymus) is Latin for twin.This was corroborated genetically by De Sá et al. (2005).The three species are most reliably distinguished by their distinctive and stereotyped advertisement call.Recordings and call characterization indicates that each species has just a single advertisement call. Leptodactylus mystaceus has a pulsed call, whereas the call of L. didymus is not pulsed (Toledo et al. 2005; Heyer et al. 1996).
As do many leptodactylid frogs, L. mystaceus males dig a nesting basin into mud near water sources, often under a log or protective vegetation.Toledo et al. (2005) report that male basin white-lipped frogs can dig extensive underground caverns about 5 cm deep.These comprise a series of connected galleries totaling at least 1 meter in length.These scientists suggest that this underground space protects them from predators.
Breeding occurs during the rainy season.Males frogs call from inside the basin or just outside the opening, beginning at dusk and continuing through the middle of the night.Females are selective.Once attracted to the male, both frogs contribute to building a foam nest, into which the female lays a mean number of 280 eggs.Rains wash the tadpoles from the foam nest into slow moving pools and ponds, where they continue to develop. The foam protects tadpoles from dessication before they are washed into pools.Research shows that if the foam breaks down before the tadpoles are washed into water, groups of tadpoles can themselves generate foam to replace it, by wriggling in their basin, activating secretions from their skin. This allows them to survive for long dry periods.A minimum number of 12 tadpoles must work together; individuals are not able to create foam alone (Caldwell and Lopez 1989).
Analysis of stomach contents from frogs near a farmhouse in Novo Progresso, Northern Brazil indicate that L. mystaceus is a generalist eater, with most of its diet made up of plant matter, beetles, and earwigs.While earwigs usually do not make up a dominant percentage of diet in this genus of frog, the presence of light from the farmhouse may have attracted them at night when frogs were foraging, an indication that this species is adaptable to habitats changed or disturbed by human activity (Camera et al. 2014).