A new pale-ventered nurse frog (Aromobatidae: Allobates) from southwestern Brazilian Amazonia

We use integrative taxonomy to formally describe a candidate species of nurse frog of the genus Allobates from southwestern Brazilian Amazonia. The new species nests within a clade that has been defined historically as A. gasconi, but it has an 8.8-11.0% genetic distance for 16S to samples from the type locality of A. gasconi. The new species differs from congeners mainly by males having a translucent white throat and vocal sac; advertisement calls with a duration of 42-60 ms, two notes separated by an inter-note interval of 8-23 ms, and a dominant frequency of 4,953-6,331 Hz; and exotrophic tadpoles with 2 pyramidal papillae on each end of the upper lip and 10-13 pyramidal and cylindrical papillae surrounding the lower lip. Phylogenetic analyses based on mitochondrial DNA suggest that A. gasconi sensu lato as defined previously represents a complex of as many as seven species, corroborating studies that have shown high levels of cryptic diversity within Allobates.