Adult: Species description based on Savage (2002). A small, delicate frog with large eyes. Females to 34 mm, males to 29 mm. Dorsal: Dorsal coloration dark green, without any spotting. The dorsal surface is smooth. Ventral: Ventral coloration white. The digestive tract visible through unpigmented skin, but the heart is not. Concealed surfaces: Males have a humeral hook, which is characteristic of this group, but the hook is not readily visible. Distinguishing characteristics: Sachatamia ilex has very prominent nostrils and a white lip line. Eye: Iris silvery grey with black reticulations. Pupil horizontal. Extremities: Feet are extensively webbed.
Egg: The eggs of Sachatamia ilex are laid on the tops of leaves on vegetation overhanging streams (Savage 2002). The eggs are black (Savage 2002). Tadpole: The tadpole of Sachatamia ilex is undescribed but Lips and Savage (1996) suggest some characteristics that it is likely to have based on the features of other Centrolenid tadpoles. In particular, they are likely to have 3 lower teethrows and 1 full and 1 partial (limited to a short segment on either side) upper toothrow (Lips and Savage 1996). Centrolenid tadpoles are fossorial, living in the low-oxygen environment under mud and leaf litter in stream bottoms (McDiarmid and Altig 1999).
Habitat: Lowland and premontane forest to 1420 m. Ecology: Populations of Sachatamia ilex are beginning to decline east of the Panama Canal due to the invasion of chytrid fungus (Woodhams et al 2008). Call: A high-pitched click (Savage 2002). Type locality: 14 km SW Amubri, Río Lari, Cantón de Talamanca, Provincia de Limon, 300 m (Costa Rica)
Diagnostic description: Medium in size from 2.7 to 3.4cm in length. Smooth upper surfaces. Head slightly wider than long, semicircular basically view from above, with nasal orificos prominently protruding and large protruding eyes. There is a white line along the upper lip. Dorsum uniformly deep green or with some small light spots. Whitish undersides. Webbed, especially well developed in the toes of the hind legs. Males have a sharp hook on the white arm. Dark green bones in living specimens. White peritoneum (Savage, 2002).
Habitat: It is usually observed on the surface of the vegetation above the beds of streams in the humid tropical forest.
Food: They feed on small insects like flies and crickets.
Behavior: They are nocturnal and arboreal.
Distribution in Costa Rica: In wetlands, low and medium, the Caribbean slope, and the lower part of the Tarcoles River Basin (San Mateo, 547m). It is located between 250-900 m elevation (Savage 2002).
Distribution outside Costa Rica: It is located on the Caribbean slope of Nicaragua, Costa Rica and Panama to western Colombia.