Telmatobius macrostomus
{{Short description|Species of amphibian}}
{{Speciesbox
| image = Rana de Junin 22.jpg
| image_caption = Lake Junin frog in captivity
| status = EN | status_system = IUCN3.1
| taxon = Telmatobius macrostomus
| authority = (Peters, 1873)
| synonyms =
Batrachophrynus microphtalmus Werner, 1901
Batrachophrynus macrostomus Peters, 1873
}}
Telmatobius macrostomus, also known as the Lake Junin (giant) frog or Andes smooth frog, is a very large and endangered species of frog in the family Telmatobiidae.{{cite web |url=http://research.amnh.org/vz/herpetology/amphibia/Amphibia/Anura/Telmatobiidae/Telmatobius/Telmatobius-macrostomus |title=Telmatobius macrostomus (Peters, 1873) |author=Frost, Darrel R. |year=2015 |work=Amphibian Species of the World: an Online Reference. Version 6.0 |publisher=American Museum of Natural History |access-date=30 May 2015}}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 to lakes and associated waters at altitudes of {{convert|4000|-|4600|m|ft|abbr=on}} in the Andes of Junín and Pasco in central Peru. It has been introduced to slow-moving parts of the upper Mantaro River, 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.{{cite book | editor1=Stuart, S. | editor2=M. Hoffmann | editor3=J. Chanson | editor4=N. Cox | editor5=R. Berridge | editor6=P. Ramani | editor7=B. Young | year=2008 | title=Threatened Amphibians of the World | pages=101, 410–419 | publisher=Lynx Edicions | isbn=978-84-96553-41-5 }}
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 Mantaro River, 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 {{cvt|12|m|ft}}, but prefers places with extensive aquatic vegetation and {{cvt|1-5|m|ft|0}} deep.{{citation | author=Castillo Roque, L. | year=2017 | title=Preferencia de microhábitat del renacuajo de Telmatobius macrostomus (Peters 1873) "rana gigante de Junín" en los afluentes del lago Chinchaycocha, Junín, Perú | publisher=Universidad Mayor de San Marcos }} In its native habitat the water temperature typically is between {{convert|7|and(-)|17|C|F|abbr=on}}.Shoobridge, D. (February 2006). Protected Area Profile Perú - Junín National Reserve, ParksWatch Perú. Captives have been kept in aquariums for more than 5 years at around {{convert|20|C|F|abbr=on}}. It feeds on aquatic snails (especially Physidae), amphipods, aquatic insects (especially Baetidae mayfly larvae) and small fish.{{cite journal | author1=Watson, A.S. | author2=A.L. Fitzgerald | author3=O.J. Damián Baldeón | year=2017 | title=Diet composition and prey selection of Telmatobius macrostomus, the Junín giant frog | journal=Endangered Species Research | volume=32 | pages=117–121 | doi=10.3354/esr00785 | doi-access=free }}
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 (T. culeus).{{cite book | author=Halliday, T. | year=2016 | title=The Book of Frogs: A Life-Size Guide to Six Hundred Species from around the World | pages=258–259 | publisher=University Of Chicago Press | isbn=978-0226184654 }} T. macrostomus measures up to {{convert|30|cm|abbr=on}} in snout–vent length, and {{convert|70|cm|abbr=on}} in total length including outstretched legs.El Observador (11 April 2011). [http://www.elobservador.com.uy/al-rescate-la-rana-gigante-peru-n109174 Al rescate de la rana gigante de Perú]. Retrieved 1 February 2017.Fjeldså, J. (1984). [http://www.sekj.org/PDF/anzf21/anzf21-411-416.pdf Three endangered South American grebes (Podiceps): case histories and the ethics of saving species by human intervention]. Ann. Zool. Fennici 21: 411–416 It can weigh up to about {{convert|2|kg|abbr=on|round=0.5}}, and the hindlegs alone can surpass {{convert|40|cm|abbr=on}} in length. Very large individuals are rare; most adults have a snout–vent length of {{convert|12.4|-|17.3|cm|abbr=on}} and weigh less than {{convert|0.5|kg|abbr=on}}. Females grow larger than males. The tadpoles also grow very large, up to about {{cvt|20|cm|in|0}} in length.
Conservation and threats
File:Ranas de JUnin peladasMercado de Huancayo.jpg
File:Ranas acuaticas desecadas.jpg
Once common, this frog is now rare and considered endangered by the IUCN. 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.{{cite journal | author1=Loza Del Carpio, A. | author2=W. Mendoza Quispe | year=2017 | title=Evaluación poblacional y estado de conservación de Telmatobius macrostomus Peters, 1873 (Anura: Telmatobiidae) en humedales altoandinos, Región Pasco-Perú | journal=Altoandin | volume=19 | issue=2 | doi=10.18271/ria.2017.273 | doi-access=free }} The primary threats to the species are capture for human consumption, predation by introduced trout, 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 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 and Ranavirus. 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 Titicaca water frog, it is planned to expand it to the Junin species at Huachipa Zoo in Lima.{{cite web | title=Saving the giant frogs of Peru, Telmatobius culeus and T. macrostomus | url=http://www.amphibianark.org/seed_grants/Lizette-Bermudez-Saving-the-giant-frogs-of-Peru.pdf | publisher=AmphibianArk | access-date=5 January 2020 }}
See also
{{Portal|Andes}}
- Goliath frog (Conraua goliath) – the world's largest frog from Africa
- Helmeted water toad (Calyptocephalella gayi) – a very large aquatic to semi-aquatic species from Chile