Oxygymnocypris stewartii

Oxygymnocypris stewartii
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cyprinidae
Genus: Oxygymnocypris
W. H. Tsao, 1964
Species: O. stewartii
Binomial name
Oxygymnocypris stewartii
(Lloyd, 1908)
Synonyms

Schizopygopsis stewartii Lloyd, 1908
Gymnocypris stewartii (Lloyd, 1908)

Oxygymnocypris stewartii is a species of cyprinid fish endemic to Tibet[2] and occurs in the Yarlung Tsangpo River (=upper Brahmaputra) and its tributaries at altitudes above 3,600 m (11,800 ft) in the Qinghai-Tibet Plateau.[1][3] It is the only species in its genus.[4]

Life history and ecology

Oxygymnocypris stewartii grows to 43 cm (17 in) SL[2] or even to 59 cm (23 in) SL.[3] It is a long-lived (to 25 years), late-maturing species that reproduces annually.[3]

Oxygymnocypris stewartii inhabits the deeper areas of clear, fast-flowing rivers with a rocky substrate.[1] It is a generalized and opportunistic predator feeding both on fish and aquatic insects. Smaller specimens feed mostly on cobitid nemacheilid loaches and caddisflies of family Hydropsychidae, whereas larger individuals switch more towards cyprinid fishes and chironomid larvae. Triplophysa stenura is the most prevalent prey species, present in 47% of stomachs, but Schizopygopsis younghusbandi contributes most (59%) to prey weight. Insects are more important in winter and spring, and fishes in summer and autumn.[3]

Fishery

Oxygymnocypris stewartii is heavily used as a food fish and is thought to be overfished.[1]

References

  1. 1 2 3 4 Ng, H.H. (2010). "Oxygymnocypris stewartii". IUCN Red List of Threatened Species. Version 2014.3. International Union for Conservation of Nature. Retrieved 8 June 2015.
  2. 1 2 Froese, Rainer and Pauly, Daniel, eds. (2014). "Oxygymnocypris stewartii" in FishBase. November 2014 version.
  3. 1 2 3 4 Huo, B.; Xie, C. X.; Madenjian, C. P.; Ma, B. S.; Yang, X. F.; Huang, H. P. (2014). "Feeding habits of an endemic fish, Oxygymnocypris stewartii, in the Yarlung Zangbo River in Tibet, China". Environmental Biology of Fishes. 97 (11): 1279–1293. doi:10.1007/s10641-013-0213-8.
  4. ↑ Eschmeyer, W. N. (2 June 2015). "Catalog of Fishes". California Academy of Sciences. Retrieved 8 June 2015.
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