Colorado pikeminnow

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Colorado pikeminnow

Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Cyprinidae
Genus:	Ptychocheilus
Species:	P. lucius

Binomial name

Ptychocheilus lucius
Girard, 1856

The Colorado pikeminnow (formerly squawfish) Ptychocheilus lucius is the largest cyprinid fish of North America, with reports of individuals up to 6 ft (1.8 m) long and weighing over 100 pounds (45 kg). Formerly an important food fish for both Native Americans and European settlers, and widespread in the Colorado River basin of the southwestern United States, its numbers and range have declined and it is now listed as an endangered species.

Like the other pikeminnows, it has an elongated body reminiscent of the pike. The cone-shaped and somewhat flattened head is elongated, nearly a quarter of the body length. Color grades from bright olive green on the back to a paler yellowish shade on the flanks, to white underneath. Young fish also have a dark spot on the caudal fin. Both the dorsal and anal fins typically have nine rays. The pharyngeal teeth are long and hooked.

The reports of 6 ft individuals are estimates from skeletal remains but a number of community elders, interviewed by the Salt Lake Tribune in 1994, reported that such individuals were once common. Catches in the 1960s ranged up to 60 cm for 11 year old fish but, by the early 1990s, maximum sizes reached no more than 34 cm. Biologists now consider the average size of an adult pikeminnow to be between 4 and 9 pounds and reports of the fish latterly exceeding 3 feet in length are now in question.

Young pikeminnows, up to 5 cm long, eat cladocerans, copepods, and chironomid larvae, then shift to insects at around 10 cm, gradually eating more fish as they mature. Once they achieve a length of about 30 cm, they feed almost entirely upon fish.

Their usual habitat is the backwaters of the turbulent and turbid rivers that make up the Colorado system.

Although once found from Wyoming to Mexico, damming and habitat alterations have reduced the species to the upper Colorado drainage; populations are known from the Green River, Gunnison River, White River, San Juan River, and Yampa River. They have been transplanted to the Salt River and Verde River, both outside their native range.

Efforts to recover the Colorado pikeminnow have thus far failed and the fish continues to decline, with the species being extirpated from most areas where it once lived. The pikeminnow has never attracted attention as a sportfish, nor is considered a highly edible species, and, hence, the recovery efforts are unpopular with many people.^{[citation needed]}

[edit] References

William F. Sigler and John W. Sigler, Fishes of Utah (University of Utah Press, 1996), pp. 109-114
"Ptychocheilus lucius". FishBase. Ed. Ranier Froese and Daniel Pauly. October 2006 version. N.p.: FishBase, 2006.