Orestias cuvieri

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Kingdom Animalia

Image: illustration from Histoire naturelle des poisons, par le baron Cuvier. Paris : Levrault, Volume 18, 1835. This image is in the public domain because its copyright has expired. This applies to the European Union, Canada, the United States and those countries with a copyright term of life of the author plus 70 years.

Phylum Chordata 
Class

Actinopterygii (Ray-finned Fish)
Order Cyprinodontiformes
Family Cyprinodontidae
Authority Valenciennes, 1846
 
English Name Lake Titicaca Orestias, Lake Titicaca Flat-Headed Fish, Amanto
Dutch Name Amanto
Chinese Name 居氏山鮰
Spanish Name Boga
 
Synonyms Orestias humboldti Valenciennes, 1846, Orestias pentlandi 
 
Comments The 1996-2008 IUCN Red Lists of Threatened Species have assessed this species as Data Deficient (DD), but note that Harrison and Stiassny (1999) consider this species to be possibly extinct (World Conservation Monitoring Centre 1996).
 
Characteristics Its mouth was so upturned as to face almost vertically and had a consequently concave head, which took up a full third of the overall body length. Full grown adults could measure 26,5 cm (10,5 in.). The adults were greenish-yellow to umber above, with a black lower jaw and black-striped fins. The scales were unusual in being very light at their centre. The young were blotched and spotted. (Day 1981)
 
Lifestyle The young are said to have congregated in deep, rock-bottomed zones in the cold season. (Day 1981)
 
Range & Habitat This fish species occurred in Lake Titicaca, situated on the border between Bolivia and Peru at an altitude of 3812 m, which makes it the highest navigable lake in the world (World Conservation Monitoring Centre 1996).
 
Food This fish was a carnivore feeding on plankton and microinvertebrates in the littoral zone. (Villwock 1972)
 
History & Population The Lake Titicaca Orestias was first collected in the 1930s. The US Fish and Wildlife Service introduced the Lake Trout (Salvelinus namaycush) in 1937 into Lake Titicaca. The Lake Titicaca Orestias disappeared from the catches of the local fishermen which used to caught this fish during its seasonal migrations. It must have become extinct during the early forties. Selective netting in 1960 failed to find a single specimen, though all the other Orestias, and the numerous Lake Trout, were present in the haul. (Day 1981; Van den Hoek Ostende 1999)
 
Extinction Causes Lake Titicaca Orestias vanished either because it could not compete with the Lake Trout (Salvelinus namaycush), which also eats fish, or because the trout preyed too heavily on juvenile Amantos. Ironically, the Lake Trout itself was destroyed in its original habitat by the Lamprey Pteromyzon marinus, introduced into the American great lakes. The trout now survives only in the South American lakes where it was introduced. (Van den Hoek Ostende 1999)
 
Museum Specimens The National Museum of Natural History 'Naturalis' in Leiden (the Netherlands) has seven specimens of the Lake Titicaca Orestias in its collection. Two specimens were recieved from the Heidelberg Museum in 1877 and one from the Smithsonian Institution in 1880. Four specimens, three juveniles and one adult, were recieved from the Muséum National d'Histoire Naturelle in Paris (France) in 1842. They were labelled as Orestias humboldti, since they had been collected before Orestias cuvieri was formally described. The label of the jar with the adult specimen from Paris bears the local name of the fish: amanto. (Van den Hoek Ostende 1999)
 
Relatives Once, Lake Titicaca contained 23 endemic species of Orestias.
 
Links IUCN Red List of Threatened Species: Orestias cuvieri
 

References

(Complete website)

 Day, D., 1981, The Doomsday Book of Animals, Ebury Press, London.

Harrison, I.J. and Stiassny, M.L.J. 1999. The Quiet Crisis. A preliminary listing of the freshwater fishes of the world that are Extinct or “Missing in Action". In: R.D.E. MacPhee (ed.) Extinctions in Near Time, pp. 271-331. Kluwer Academic/Plenum Publishers, New York.

Huber, J.H., 1996. Killi-Data 1996. Updated checklist of taxonomic names, collecting localities and bibliographic references of oviparous Cyprinodont fishes (Atherinomorpha, Pisces).. Société Française d'Ichtyologie, Muséum National d'Histoire Naturelle, Paris, France, 399 p.

Van den Hoek Ostende, L.W. 1999. Amanto - Driven out by trout.  300 Pearls - Museum highlights of natural diversity. Downloaded on 18 December 2005.

Villwock, W., 1972. Gefahren für die endemische Fischfauna durch Einbürgerungsversuche und Akklimatisation von Fremdfischen am Beispiel des Titicacas-Sees (Peru/Bolivien) und des Lanao-Sees (Mindanao/Philippinen).. Verh. Internat. Verein. Limnol. 18(1227-1234).

World Conservation Monitoring Centre 1996. Orestias cuvieri. In: IUCN 2004. 2004 IUCN Red List of Threatened Species. <www.redlist.org>. Downloaded on 27 November 2005.

Last updated: 25th December 2008.

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