Adult: Species description based on Savage (2002). A small to medium-sized frog. Females grow much larger than males (to 44 versus 31 mm). Dorsal: The dorsal surface is black with two distinct yellow, orange or red dorsolateral stripes that run from behind the eye to at least halfway down the body. Ventral: The ventral surface is usually grey, but may be orangeish or greenish-blue with some lighter or darker patterning. This coloration is often visible on the lateral surfaces as well. Eye: Eye coloration ranges from orange to orange-brown to bronze. The upper and lower halves of the eye are separated by a thin black line.
Habitat: Lowland rainforest to 200 m. Ecology: A noctornal leaf litter inhabitant (Savage 2002). Behavior and communication: Movement (short hops) of Pristimantis gaigei mimics that of dendrobatids as well as coloration (Savage 2002). Evolotion: Lynch (1985) outlines the evidence against mimicry in Pristimantis gaigei. Savage (2002) also discusses this issue. Type locality: Fort Randolph, Panama Canal Zone
Diagnostic description: The legs lacking webbing. L finger of the hand is longer than the ll, l or ll have a similar size. The fingers of the hands and feet usually lack well-defined disks. Lll and lV The fingers of the hands and feet have expanded discs. The back is uniformly granular, black color, with a pair of dorsal stripes extending from the eye to the sacrum (the stripes disappear in preservative).
Adult males lack nuptial pads and vocal slits thumbs.
The maximum standard length in males adult specimens is 30 mm. and females is 43 mm.
Reproduction: Encapsulated produce eggs which are laid in terrestrial conditions, with direct development (no tadpoles) (Savage 2002).
Distribution in Costa Rica: In the lowlands southeast end of the Atlantic slope, Valle de Talamanca, between 20 and 200 m. Lift (Savage 2002).
Distribution outside Costa Rica: It is found from Costa Rica to central Choco to western Colombia. Also located in the Andean valleys of Colombia.