Among its western clade relatives, Acrocheilus is sympatric with Ptychocheilus
Burley & Vigg (1989), with coho salmon Oncorhynchus kisutch (Walbaum, 1792) and northern squawfish Ptychocheilus
oregonensis (Richardson, 1836), using their method based on a maximum expansion of the stomach which consisted of filling the stomach with air under pressure provided by a cylinder of gas.
Bestgen and Bundy (1998) reported that increments deposited on the sagittae of Colorado pikeminnow (Ptychocheilus
lucius) were difficult to distinguish after the fish were 30 days old.
Similar to humpback chub and bonytail, voltage gradients <1.00 V/cm resulted in immobilization of rainbow trout, Oncorhynchus mykiss, (0.22 and 0.32 V/cm) and Colorado pikeminnow, Ptychocheilus
lucius, (0.63 and 0.20 V/cm) using pulse frequencies of 15 and 60 Hz, respectively, in ambient water conductivity of 530 [micro]S/cm (Meismer, 1999).
Predation and competition by nonnative fishes threatens the survival of these native species--their presence in the basin has been particularly damaging to the federally endangered bonytail (Gila elegans), humpback chub (Gila elegans), Colorado pikeminnow (Ptychocheilus
lucius), and razorback sucker (Xyrauchen texanus).
Development and intensity dependence of Ornithodiplostomum ptychocheilus
metacercariae in fathead minnows (Pimephales promelas).
Fish extinctions (e.g., Snake River sucker Chasmistes muriei) and extirpations (e.g., Colorado pikeminnow Ptychocheilus
lucius from the lower Colorado River) in North America are most numerous in the West where reservoir construction, non-native fish introductions and water withdrawals altered habitat and established new predators and competitors for native fishes (Minckley and Douglas, 1991).
Lin D, Morrissey MT (1994) Iced storage characteristics of Northern squawfish (Ptychocheilus
These changes contributed to the decline of the razorback sucker and three other fish species that exist nowhere else on earth: the humpback chub (Gila cypha), bonytail (Gila elegans), and Colorado pikeminnow (Ptychocheilus
Changes in habitat and microhabitat partitioning within an assemblage of stream fishes in response to predation by Sacramento squawfish (Ptychocheilus
a pikeminnow (Ptychocheilus
lucius), a topminnow (Poeciliopsis