Humpback chub

Taxobox

---

status = VU | status_system = IUCN2.3
name = Humpback chub
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Cypriniformes
familia = Cyprinidae
genus = "Gila"
species = "G. cypha"
binomial = "Gila cypha"
binomial_authority = Miller, 1946

The humpback chub "Gila cypha", is a rare fish found only in fast waters of the Colorado River system in the United States. It takes its name from the prominent hump between the head and dorsal fin, which directs the flow of water over its body in such a way as to help it maintain its position in the swift currents of the Colorado. The body is almost entirely scaleless, retaining only about 80 mid-lateral scales along the lateral line. The fish is very streamlined, with a thin caudal peduncle and a deeply forked tail. The back is a light olive gray, the sides silver, and the belly white. The dorsal fin usually has nine rays, and the anal fin 10 or more. Maximum recorded length is 38 cm.

Humpback chubs mostly consume invertebrates and, to a lesser extent, other fish. They feed at all levels from the bottom to the surface. The species spawns from April through June, at water temperatures of 66-70°F. The males develop nuptial tubercles on the head and paired fins. The fish spawn in slower-moving backwaters, typically over a substrate of cobbles or boulders. Young fish stay near shore and in quiet areas, preferring slightly more turbid water.

Populations are known only from the Colorado and several of its tributaries; the Green River, White River, Yampa River, and the Little Colorado River. It is possible that populations once existed in the Lower Colorado, but since the species was only described in the 1940s, after the Colorado had been extensively modified, the full original range is unknown.

Efforts to recover the fish have thus far failed and the fish has been extirpated from many areas it once inhabited. The humpback is not considered a sportfish, so recovery efforts are unpopular with many people.Fact|date=November 2007

References

* William F. Sigler and John W. Sigler, "Fishes of Utah" (University of Utah Press, 1996), pp. 79-83
*FishBase_species|genus=Gila|species=cypha|year=2006|month=October
* [http://ecos.fws.gov/docs/life_histories/E000.html FWS page]