Telmatobius culeus

Titicaca water frog
Illustration by Samuel Garman, 1876
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Amphibia
Order:Anura
Family:Telmatobiidae
Genus:Telmatobius
Species: T. culeus
Binomial name
Telmatobius culeus
(Garman, 1876)

Telmatobius culeus, commonly known as the Titicaca water frog, is a very large and critically endangered species of frog in the family Telmatobiidae.[2] It is entirely aquatic and only found in Lake Titicaca and rivers that flow into this lake in the Andean highlands of South America.[3] In reference to its excessive amounts of skin, it has jokingly been referred to as the Titicaca scrotum water frog.[4]

It is closely related to the smaller, more widespread and semi-aquatic marbled water frog (T. marmoratus),[5][6] which also occurs in coastal parts of Lake Titicaca.[7]

Appearance

While the lungs are greatly reduced, this frog has excessive amounts of skin, used to help the frog respire in the cold water in which it lives.[3][8] The color is highly variable, but generally gray, brown or greenish above, and paler below.[9]

In 1968, an expedition led by Jacques Cousteau reported frogs up to 50 cm (20 in) in outstretched length and 1 kg (2.2 lb) in weight[10],[11] making these some of the largest exclusively aquatic frogs in the world (the fully aquatic Lake Junin frog is larger, as is the African goliath frog, which sometimes can be seen on land).[8] The snout-vent length is typically 7.5–13.8 cm (3.0–5.4 in).[3][8] Females grow larger than males.[9]

Ecology and behavior

The Titicaca water frog spends its entire life in oxygen-rich water[3] that typically is 10–17 °C (50–60 °F).[12] It mainly stays near the bottom and it does not surface to breathe if the water is well-oxygenated.[3] It regularly performs "push-ups" to allow water to pass by its large skin folds, which absorb oxygen.[12] It occurs even in deeper parts of Lake Titicaca,[8] although the limit is unknown.[12] The Titicaca water frog feeds on amphipods, insects, snails, tadpoles and fish (including Orestias).[3] It has an extremely low metabolic rate; below that of all other frogs.[3] Breeding is in shallow, coastal water where the female lays about 500 eggs.[3]

Conservation status

Once common, the Titicaca water frog has declined drastically and is now facing extinction due to over-collecting for human consumption, pollution, and predation of tadpoles by introduced trout.[2] It may also be threatened by the disease chytridiomycosis.[2] It is estimated that it has declined by more than 80% in the last three Titicaca water frog generations, equalling 15 years.[3][13] Several other species in the genus Telmatobius are facing similar risks.[2]

In the last few years, mass deaths have occurred several times. In April 2015, thousands of dead Titicaca water frogs were found in Bolivia on the shore of Lake Titicaca[13] and in October 2016 an estimated 10,000 were found dead in the Coata River (a Lake Titicaca tributary). At least in the latter case, scientists believe pollution killed the frogs.[14][15]

Conservation projects for the Titicaca water frog have been initiated, including studies to find the reason for the mass deaths and an attempt at establishing a secure captive population that may form the basis for future reintroductions into places where it has disappeared.[13][16][17] Earlier captive breeding attempts were unsuccessful,[3] but projects started in 2010 have succeeded in breeding the species at facilities in both Cochabamba (Bolivia) and Lima (Peru).[12][18] In 2016, the project was expanded when a group of Titicaca water frogs was sent to Denver Zoo in the United States.[12] The first North American captive breeding happened at the zoo in February 2017 when about 200 tadpoles hatched.[19] Captives have lived for up to 20 years.[12]

International trade of Titicaca water frogs is restricted, as the species is included on CITES Appendix I.[20]

References

  1. ↑ Icochea, J.; Reichle, S.; De la Riva, I.; Sinsch, U.; Köhler, J. (2004). "Telmatobius culeus". IUCN Red List of Threatened Species. IUCN. 2004: e.T57334A11623098. Retrieved 9 April 2016.
  2. 1 2 3 4 Stuart, Hoffmann, Chanson, Cox, Berridge, Ramani and Young, editors (2008). Threatened Amphibians of the World. ISBN 978-84-96553-41-5
  3. 1 2 3 4 5 6 7 8 9 10 Amphibiaweb (2010). Telmatobius culeus. University of California, Berkeley, CA, USA. Retrieved 9 February 2017.
  4. ↑ Victoria Gill (12 September 2013). "Blobfish wins ugliest animal vote". BBC News. Retrieved 12 September 2013.
  5. ↑ Victoriano, Muñoz-Mendoza, Sáez, Salinas, Muñoz-Ramírez, Sallaberry, Fibla and Méndez (2015). Evolution and Conservation on Top of the World: Phylogeography of the Marbled Water Frog (Telmatobius marmoratus Species Complex; Anura, Telmatobiidae) in Protected Areas of Chile. J.Hered. 106 (S1): 546-559. DOI: 10.1093/jhered/esv039
  6. ↑ De la Riva , García-París, and Parra-Olea (2010). Systematics of Bolivian frogs of the genus Telmatobius (Anura, Ceratophryidae) based on mtDNA sequences. Systematics and Biodiversity 8(1): 49–61. DOI: 10.1080/14772000903526454
  7. ↑ Cossel, Lindquist, Craig, and Luthman (2014). Pathogenic fungus Batrachochytrium dendrobatidis in marbled water frog Telmatobius marmoratus: first record from Lake Titicaca, Bolivia. Dis Aquat Organ. 112(1):83-7. doi: 10.3354/dao02778
  8. 1 2 3 4 Halliday, T. (2016). The Book of Frogs: A Life-Size Guide to Six Hundred Species from around the World. University Of Chicago Press. ISBN 978-0226184654
  9. 1 2 "Telmatobius culeus". Bolivian Amphibian Initiative. Retrieved 8 February 2017.
  10. ↑ https://www.filmaffinity.com/en/film831399.html
  11. ↑ Quinn, J.A.; & S.L. Woodward, editors (2015). Earth's Landscape: An Encyclopedia of the World's Geographic Features. P. 404. ISBN 978-1610694452
  12. 1 2 3 4 5 6 Pappas, S. (27 April 2016). "Dying Breed? Zoo Toils to Save Strange 'Scrotum Frog'". Live Science. Retrieved 9 February 2017.
  13. 1 2 3 Titicaca water frog, Stiftung Artenschutz, retrieved 8 February 2017
  14. ↑ Howard, Brian Clark (19 Oct 2016). "10,000 'Scrotum Frogs' Die Mysteriously in Lake Titicaca". National Geographic. Retrieved 19 October 2016.
  15. ↑ Collyns, Dan (19 Oct 2016). "Scientists investigate death of 10,000 endangered 'scrotum' frogs in Peru". The Guardian. Retrieved 19 October 2016.
  16. ↑ "Titicaca: Equipo internacional rescata a la rana gigante". Erbol Digital. 2 March 2016. Retrieved 8 February 2017.
  17. ↑ "Rescuing Titicaca Water Frog". Bolivian Amphibian Initiative. Retrieved 8 February 2017.
  18. ↑ Mendoza Miranda, D.P. Clark; Munoz, A. "Ampliacíon del Programa de Cría en Cautiverio de género Telmatobius en Cochabama" (PDF). Bolivian Amphibian Initiative. Retrieved 8 February 2017.
  19. ↑ "Denver Zoo hatches first Lake Titicaca frog tadpoles in North American history". Denver Zoo. 15 May 2017. Retrieved 29 October 2017.
  20. ↑ "Appendices I, II and III". CITES. 4 October 2017. Retrieved 26 October 2017.
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