''Telmatobius macrostomus'', also known as the Lake Junin (giant) frog or Andes smooth frog, is a very large and

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

species of

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

in the family Telmatobiidae.Angulo, A. (2008). "Conservation needs of Batrachophrynus and Telmatobius frogs of the Andes of Peru." Conservation & Society 6(4): 328–333. DOI: 10.4103/0972-4923.49196 This completely aquatic frog is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to lakes and associated waters at altitudes of in the

Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

of Junín and Pasco in central

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

. It has been introduced to slow-moving parts of the upper

Mantaro River The Mantaro River (, ) is a long river running through the central region of Peru. Its Quechua name means "great river". The word "Mantaro" may be a word originally from the Asháninka language, who live downstream along the Ene River. The Mantar ...

, although it is unclear if this population still persists.Sinsch, U. (1990). ''Froschlurche (Anura) der zentral-peruanischen Anden: Artdiagnose, Taxonomie, Habitate, Verhaltensökologie.'' Salamandra 26(2/3): 177- 214. Together with the closely related Amable Maria frog (''T. brachydactylus''), it is sometimes placed in the genus '' Batrachophrynus''.

Ecology and appearance

''T. macrostomus'' is completely aquatic, and restricted to lakes (notably Lake Junín) and waters that are directly connected to them like rivers, streams and canals. It has also been introduced to the upper part of the

, but it is unclear if this population persists. It is found both in large marshy lakes and smaller deep lakes. This smooth-skinned, dark brownish frog generally ranges from shallow water to a depth of , but prefers places with extensive aquatic vegetation and deep. In its native habitat the water temperature typically is between . Captives have been kept in aquariums for more than 5 years at around . It feeds on aquatic snails (especially Physidae),

amphipod Amphipoda () is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods () range in size from and are mostly detritivores or scavengers. There are more than 10,700 amphipod species cur ...

s, aquatic insects (especially Baetidae mayfly larvae) and small fish. ''T. macrostomus'' is among the largest frogs in the world and the largest exclusively aquatic frog, a title sometimes incorrectly awarded to its somewhat smaller relative, the

Titicaca water frog ''Telmatobius culeus'', commonly known as the Titicaca water frog or Lake Titicaca frog, is a medium-large to very large and endangered species of frog in the family Telmatobiidae. It is entirely aquatic and found only in the Lake Titicaca basi ...

(''T. culeus''). ''T. macrostomus'' measures up to in

snout–vent length Snout–vent length (SVL) is a morphometric measurement taken in herpetology from the tip of the snout to the most posterior opening of the cloacal slit (vent)."direct line distance from tip of snout to posterior margin of vent" It is the mos ...

, and in total length including outstretched legs.El Observador (11 April 2011).
Al rescate de la rana gigante de Perú
'' Retrieved 1 February 2017. It can weigh up to about , and the hindlegs alone can surpass in length. Very large individuals are rare; most adults have a snout–vent length of and weigh less than . Females grow larger than males. The

tadpole A tadpole or polliwog (also spelled pollywog) is the Larva, larval stage in the biological life cycle of an amphibian. Most tadpoles are fully Aquatic animal, aquatic, though some species of amphibians have tadpoles that are terrestrial animal, ...

s also grow very large, up to about in length.

Conservation and threats

Ranas de JUnin peladasMercado de Huancayo

Once common, this frog is now rare and considered

by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

. During a survey in 2012 it was only found at about 10% of the visited sites and in low densities, leading to the suggestion of recognizing it as

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

. The primary threats to the species are capture for human consumption, predation by introduced

trout Trout (: trout) is a generic common name for numerous species of carnivorous freshwater ray-finned fishes belonging to the genera '' Oncorhynchus'', ''Salmo'' and ''Salvelinus'', all of which are members of the subfamily Salmoninae in the ...

, pollution from mining, agriculture and human waste, and water fluctuations caused by the Upamayo Dam. These factors have also contributed to the decline of the native ''

Orestias Orestias (), later refounded by Hadrian as Adrianople (Greek: Άδριανούπολις), was an ancient Greek settlement next to the Evros river in Thrace, near or at the site of present-day Edirne, and close to the current border between Turk ...

'' pupfish, historically an important part of the diet of the frog, but not recorded in a recent study of its diet. Although not yet detected in ''T. macrostomus'', some of its relatives have strongly declined due to diseases like

chytridiomycosis Chytridiomycosis ( ) is an infectious disease in amphibians, caused by the chytrid fungi '' Batrachochytrium dendrobatidis'' and '' Batrachochytrium salamandrivorans''. Chytridiomycosis has been linked to dramatic population declines or extinc ...

and ''

Ranavirus ''Ranavirus'' is a genus of viruses in the family ''Iridoviridae''. There are six other genus, genera of viruses within the family ''Iridoviridae'', but ''Ranavirus'' is the only one that includes viruses that are infectious to amphibians and r ...

''. Mass deaths have occurred in ''T. macrostomus'', with a particular large one in 1996, but the reason for this is unknown. Much of its range is within reserves, but protection is insufficient. Local and national groups, partially funded internationally, have started monitoring and conservation projects for this species, and education for the people living in its range. In 2008, an experimental captive breeding program was initiated at two centers at Lake Junin and it resulted in a few thousand tadpoles, but this project ceased in 2012. Following progress and success with the captive breeding program for the related

, it is planned to expand it to the Junin species at Huachipa Zoo in

Lima Lima ( ; ), founded in 1535 as the Ciudad de los Reyes (, Spanish for "City of Biblical Magi, Kings"), is the capital and largest city of Peru. It is located in the valleys of the Chillón River, Chillón, Rímac River, Rímac and Lurín Rive ...

References

{{Taxonbar, from=Q306825 macrostomus Amphibians of the Andes Amphibians of Peru Endemic fauna of Peru Endangered animals Endangered biota of South America Taxonomy articles created by Polbot Amphibians described in 1873 Taxa named by Wilhelm Peters

Ecology and appearance

Conservation and threats

See also

References