Ptychocheilus

Ptychocheilus, the pikeminnows or squawfish, is a genus of freshwater ray-finned fishes belonging to the family Leuciscidae, which includes the daces, chubs, Eurasian minnows and related species.^[1] These fishes are native to western North America. Voracious predators, they are considered an "undesirable" species in many waters, largely due to the species' perceived tendency to prey upon small trout and salmon. First known in western science by the common name Columbia River dace, the four species all became lumped under the name "squawfish". In 1999, the American Fisheries Society adopted "pikeminnow" as the name it recommends, because Native Americans consider "squawfish" offensive.^[2]

Ptychocheilus Temporal range: Late Miocene to present PreꞒ Ꞓ O S D C P T J K Pg N Possible Late Eocene occurrence
Colorado pikeminnow (Ptychocheilus lucius)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Leuciscidae
Subfamily:	Laviniinae
Genus:	Ptychocheilus Agassiz, 1855[1]
Type species
Ptychocheilus gracilis Agassiz & Pickering, 1855[1]
Species
See text

This article is about the genus. For other uses, see Squawfish (disambiguation).

The Colorado pikeminnow, P. lucius, is the largest member of the genus, ranging from 4–9 lb (2–4 kg) in adult fish with occasional specimens up to 25 lb (11 kg). Historical and anecdotal reports of Colorado pikeminnows nearing 6 feet (1.8 m) in length and 80 lb (36 kg) in weight have been made. The species is near extinction in its native Colorado River Basin habitat, due to extensive habitat destruction.

On the Columbia and Snake rivers from approximately May through September anglers are paid for each northern pikeminnow that they catch (from within program boundaries) that is 9 inches (23 cm) or larger in total length, and the more you catch, the higher the reward. Rewards begin at $5 each for the first 25 northern pikeminnow caught during the season. Anglers are paid $6 for each they catch from 26–200 fish, and $8 for every fish caught over 200 cumulatively. Anglers are also paid $500 for each specially tagged northern pikeminnow.^[3]

Species

The four recognized species are:^[4]

Ptychocheilus grandis	(Ayres, 1854)	Sacramento pikeminnow
Ptychocheilus lucius	(Girard, 1856)	Colorado pikeminnow
Ptychocheilus oregonensis	(J. Richardson, 1836)	northern pikeminnow
Ptychocheilus umpquae	(Snyder, 1908)	Umpqua pikeminnow

Two fossil species are also known:^[5]

• †Ptychocheilus arciferus Cope, 1870 (Pliocene of Idaho)
• †Ptychocheilus prelucius Uyeno & Miller, 1965 (Late Miocene-aged Bidahochi Formation of Arizona)^[6][7]

In addition, the partial fossils of a large minnow with presumed affinities to Ptychocheilus have been recovered from the Late Eocene or Early Oligocene-aged deposits of the Cypress Hills Formation in Saskatchewan.^[8]