Adult: Species description based on Ibanez et al (1999) and Savage (2002). A large frog with a pointed snout (males to 95 mm, females to 120 mm). Males have much more robust arms than females, and two black spines on the thumbs. Dorsal: The dorsum is dark brown with large, darker brown spots. A white stripe is present along the upper lip. The dorsum is smooth except for two prominent folds running dorsolaterally down the back. The arms and legs are usually barred. Ventral: The ventral surface is white to cream with some darker pigmentation. The pigmentation is heavier on the throat. Concealed surfaces: The rear surfaces of the thighs are brown, with some white or yellow spots. Eye: The iris is bronze. Extremities: The hands are unwebbed, but the feet have some non-extensive webbing.
Breeding season: Breeding occurs throughout the rainy season and but males call occasionally during the dry season (Ibanez et al 1999, Savage 2002). Breeding typically occurs in open, flooded grassy areas or along the banks of more permanent water bodies such as rivers (Ibanez et al 1999, Savage 2002). Egg: Eggs are deposited in a foamy nest formed by the male kicking and aerating the jelly surrounding the eggs (Heyer and Rand 1977, Savage 2002). As many as 2,000 eggs may be deposited in a single nest (Savage 2002). Tadpole: Tadpole bodies are oval, with a long, muscular tail (Savage 2002). Tadpole bodies are very dark brown, with some gold flecking on the tail (Savage 2002). The ventral surface is lighter (Savage 2002). Tadpoles live in dense schools (Wells and Bard 1998).
Habitat: Lowland and premontane forest to 1400 m. Also found in more disturbed areas. Call: A short, low, musical "bluup" rather like the sound of a bubble popping (Fouquette 1960, Straughan and Heyer 1976, Ibanez et al 1999). The vocal sac is internal (Ibanez et al 1999, Savage 2002). Behavior and communication: Nests are hidden in vegetation and debris (Savage 2002). Males remain near nests (Savage 20020. Females attend and defend both nests and tadpoles (Wells and Bard 1988, Vaira 1997). Females use characteristic pumping motions to communicate with tadpoles (Wells and Bard 1988). Karyotype: 2N = 22 (Bogart 1974) Type locality: Barraca (Bolivia) Diet: The diet consists primarily of arthropods, but large individuals will consume other kinds of prey (Savage 2002).