Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Amphibia Anura Bufonidae

Scientific Name: Atelopus balios
Species Authority: Peters, 1973
Common Name(s):
English Rio Pescado Stubfoot Toad
Taxonomic Source(s): Frost, D.R. 2014. Amphibian Species of the World: an Online Reference. Version 6 (27 January 2014). New York, USA. Available at: (Accessed: 27 January 2014).

Assessment Information [top]

Red List Category & Criteria: Critically Endangered (Possibly Extinct) A2ace ver 3.1
Year Published: 2004
Date Assessed: 2004-04-30
Needs updating
Assessor(s): Diego Cisneros-Heredia, Mario Yánez-Muñoz, Luis A. Coloma, Santiago Ron
Reviewer(s): Global Amphibian Assessment Coordinating Team (Simon Stuart, Janice Chanson, Neil Cox and Bruce Young)
Listed as Critically Endangered because of a drastic population decline, estimated to be more than 80% over the last three generations, inferred from the apparent disappearance of most of the population, probably due to chytridiomycosis.
Date last seen: 1995

Geographic Range [top]

Range Description: This species is known from only four localities in Azuay, Cañar, and Guayas Provinces in the Pacific lowlands of south-western Ecuador, from 200-460m asl.
Countries occurrence:
Possibly extinct:
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: This is now considered a very rare species. There have been no records since April 1995 despite repeated searches. It is no longer found at Río Patul (in Azuay province), where it used to be abundant (L. Coloma pers. comm.).
Current Population Trend: Decreasing
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: It is an inhabitant of lowland rainforest, and has been found on riverbanks. There is no specific information known about breeding habits, though it is likely to be similar to other Atelopus species, with breeding taking place in streams.
Systems: Terrestrial; Freshwater

Threats [top]

Major Threat(s): This species seems to have disappeared, as with many other Atelopus species, likely due to chytridiomycosis, although the altitude at which it occurs is low (the disease normally occurs at higher altitudes in the tropics). Habitat degradation and loss, due to agriculture (crops and livestock) and logging, and pollution, continue to be very serious threats.

Conservation Actions [top]

Conservation Actions: The range of the species does not include any protected areas. As the species might be extinct, it might be too late for conservation measures such as captive breeding; additional survey work is required to confirm the continued persistence of this species in the wild.

Citation: Diego Cisneros-Heredia, Mario Yánez-Muñoz, Luis A. Coloma, Santiago Ron. 2004. Atelopus balios. The IUCN Red List of Threatened Species 2004: e.T54491A11141869. . Downloaded on 13 October 2015.
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