Adult: Species description based on Savage (2002). A small, delicate frog with large eyes. Males have a blunt humeral hook. Dorsal: The smooth dorsal skin is light green, often with small black spots. Ventral: The ventral surface is pale yellow. The heart is not visible in this species, although the digestive tract is. Eye: Iris grayish white with a fine black reticulations. Pupil horizontal. Extremities: Feet are moderately webbed.
Breeding season: Males call from the tops of leaves and even continue to call in amplexus (Jacobson 1985). In Monteverde, Costa Rica, eggs were laid from the end of June through August-September (Jacobson 1985). Egg: Eggs are laid on vegetation overhanging streams or on moss-covered rocks (Jacobson 1985). Each clutch contains 20 or so small, black eggs, thinly surrounded by jelly (Savage 2002). Embryos turn from black to yellow to bright red by the time they hatch (Savage 2002). Tadpole: A description of the tadpoles can be found in Starrett (1960). Tadpole bodies are elongate, with a long tail with shallow tail fins (Starrett 1960, Savage 2002). The mouth is oriented ventrallly and has two upper and three lower teethrows (Starrett 1960). The upper toothrow closest to the opening of the mouth is limited to two short segments (Starrett 1960). The tadpoles appear bright red due to large concentrations of hemoglobin in the blood (Savage 2002). Centrolenid tadpoles are fossorial, living in the low-oxygen environment under mud and leaf litter in stream bottoms (McDiarmid and Altig 1999).
Habitat: Lowland rainforest and montane cloud forest to 1500 m. Ecology: Selection of moist microhabitats for clutch deposition (i.e. moist, mossy substrate) increased the likelihood of clutch survival (Jacobson 1985). Call: A three note dik, dik, dik (Savage 2002). Behavior and communication: Female E. prosoblepon attend clutches of eggs immediately after deposition, but do not return on subsequent nights (Jacobson 1985). Clutch attendance does not appear to enhance the success of their offspring (Jacobson 1985). Males use calling to establish territories and space themselves in the environment (Jacobson 1985). Males rarely wrestle (Jacobson 1985). Karyotype: 2N = 20 (Duellman 1967) Evolotion: Espadaran prosoblepon males show strong site fidelity, rarely moving among streams, and gene flow among populations is limited by distance (Robertson et al 2008). However, populations in headwater streams may sometimes be supplemented by the uphill migration of more lowland populations (Robertson et al 2008). Type locality: Plantage Cairo (La Junta) bei Limon, [Cantón de Siquirres, Provincia de Limón,] atlantische Seite von Costa Rica Physiology: The skin of E. prosoblepon reflects light in the near infra-red (Schwam et al 1977). Schwam et al (1977) hypothesized that the advantages of infrared reflectance could be related to thermoregulation or predator avoidance.