Brook frog  (Duellmanohyla soralia)

Classified as Critically Endangered (CR) on the IUCN Red List (1).

The markings of olive, green and black that pattern the brown back of Duellmanohyla soralia almost resembles lichen growing on a branch, hence the specific name soralia, a Greek word that refers to lichen reproduction. The irises of this tiny frog are bright red, and the underside of the body is golden yellow. The slender tadpole has a robust tail, low fins, and a large, funnel-shaped mouth, and is yellowish olive-green in colour with iridescent pale green spotting. The call of the adult male is a single low-pitched "peep", repeated every 20 to 30 seconds (2).

Occurs in northwestern Honduras and northeastern Guatemala, from 40 to 1,570 metres above sea level (1) (2).

Breeding and larval development takes place in streams in lowland moist forest, submontane forest and lower montane forest. The adults have been found at night in low vegetation adjacent to streams (1) (2).

Little is known about the biology of Duellmanohyla soralia, but like all species in the subfamily Hylinae, it has free-swimming tadpoles. Duellmanohyla soralia tadpoles have been seen schooling from May to August, sometimes swimming upside down at the surface of quiet pools, or alternatively resting on rocks on the stream bottom (2).

Owing to agriculture, logging and water pollution, Duellmanohyla soralia is declining throughout its restricted range and the remaining populations are severely fragmented. Most recently, the deadly amphibian fungal disease chytridiomycosis has been detected in the population, with between 45 to 60 percent of all larvae infected (1) (2).

Duellmanohyla soralia occurs within two protected areas in Honduras, Parque Nacional Cerro Azul and Parque Nacional Cusuco, although habitat loss still continues in the latter. Given the spectre of fungal disease spreading through the entire population, it is important that the population status of this Critically Endangered species is closely monitored (1) (2).

View information on this species at the UNEP World Conservation Monitoring Centre.

To find out more about the conservation of amphibians see:

• IUCN Amphibian Specialist Group:
  http://www.amphibians.org/
• Amphibian Ark:
  http://www.amphibianark.org/
• Gascon, C., Collins, J.P. Moore, R.D., Church, D.R., McKay, J.E. and Mendelson III, J.R. (2007) Amphibian Conservation Action Plan. IUCN/SSC Amphibian Specialist Group, Gland, Switzerland and Cambridge, UK. Available at:
  http://data.iucn.org/dbtw-wpd/edocs/2007-013.pdf