Orestias (fish)

Orestias
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cyprinodontiformes
Family:	Cyprinodontidae
Genus:	Orestias Valenciennes, 1839
Species
About 43, see text.

Orestias is a genus of pupfish. Older systematics classified them into the own family Orestiidae. They are carnivorous plankton feeders and can reach a length between 9 and 22 centimetres. Their most characteristic feature is the absence of the ventral fin. They are endemic in the Lake Titicaca and other lakes of the Altiplano in Peru, Bolivia, and Chile in an altitude up to 3,600 metres asl. Many species of that genus became rare in the past decades due to the competition with introduced fish species, pollution and human activities at the lakes. One species - the Titicaca Orestias (Orestias cuvieri) - was last seen in 1939 and is probably extinct; several others are known only very restricted ranges (Parenti 1984). Several species are colloquially known as carache.

Systematics

The following 43 species belonging to the genus Orestias were divided by American ichthyologist Lynne R. Parenti depending on their relationships into four species complexes in 1984. Lüssen (2003) researched the phylogeny of several species including mtDNA sequence data; due to hybridization being known to occur (Villwock 1964, Parenti 1984), mtDNA data cannot be relied upon to resolve the evolution of this genus on its own.

Agassii species complex

• Orestias agassizii - Carache Negro
• Orestias albus - Carache Amarillo
• Orestias ascotanensis
• Orestias chungarensis
• Orestias ctenolepis
• Orestias elegans
• Orestias empyraeus
• Orestias frontosus
• Orestias gymnotus
• Orestias hardini
• Orestias jussiei - Carache Amarillo
• Orestias lastarriae
• Orestias laucaensis
• Orestias luteus - Carache Amarillo
• Orestias multiporis
• Orestias mundus
• Orestias olivaceus
• Orestias parinacotensis
• Orestias polonorum
• Orestias puni
• Orestias richersoni
• Orestias rotundipinnis
• Orestias silustani
• Orestias tschudii
• Orestias ututo

Cuvieri species complex

• Orestias cuvieri - Titicaca Orestias, Amanto; extinct (mid-20th century)
• Orestias forgeti - Ispi
• Orestias ispi - Ispi
• Orestias pentlandii - Boga

Gilsoni species complex

• Orestias gilsoni
• Orestias imarpe
• Orestias minimus
• Orestias minutus
• Orestias mooni
• Orestias robustus
• Orestias taquiri
• Orestias tchernavini
• Orestias tomcooni
• Orestias uruni

Mulleri species complex

• Orestias crawfordi
• Orestias gracilis
• Orestias incae
• Orestias mulleri
• Orestias tutini

References

• Lüssen, Arne (2003): Zur Systematik, Phylogenie und Biogeographie chilenischer Arten der Gattung Orestias VALENCIENNES, 1839. Doctoral thesis, University of Hamburg, Germany. [in German] PDF fulltext

• Parenti, Lynne R. (1984): A taxonomic revision of the Andean Killifish Genus Orestias (Cyprinodontiformes, Cyprinodontidae). Bulletin of the American Museum of Natural History 178: 107-214. PDF fulltext

• Villwock, W. (1964): Vermeintliche Artbastarde in der Gattung Orestias (Pisces, Cyprinodontidae). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, Kosswig-Festschrift: 285-291. [Article in German]

• 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). Verhandlungen des Internationalen Vereins für Limnologie 18: 1227-1234. [Article in German]