7621

• UCREFRP Catalog Number: 7621
• Author: Woodling, J.
• Title: Colorado's Little Fish
• USFW Year: 1985.
• USFW - Doc Type: A Guide to the Minnows and Other Lesser Known Fishes in the State of Colorado.
• Copyright Material: NO

longnose dace according to the principal
characteristic used to separate these two
species. Wiltzius (1978) reported the long-
nose dace as being present in the Gunni-
son River system upstream of Blue Mesa
Reservoir. If longnose dace are found in
the Gunnison drainage, both species of
dace would be maintaining reproductive
isolation even though they often share the
same stream reach. Accurate separation
of these two species, knowledge of correct
distribution patterns and verification of
the presence or absence of sympatric pop-
ulations requires more analysis.

COLORADO
SQUAWFISH
Ptychocheilus lucius
(Girard)
An elongated minnow, body com-
pressed somewhat dorso-ventrally; head
flattened and elongated, large mouth,
nearly horizontal; dorsal and anal fins with
9 rays; scales small, 80-95 in lateral line,
small and embedded on nape, ventral
area and chest; pharyngeal teeth fragile
and delicate, 2, 5-4, 2.
Adults are darker than young, oliva-
ceous above with a white stomach. Young
squawfish, up to about 10 inches, have a
dark blotch on the base of the tail. This
blotch is absent in the roundtail chub, a
species which can be mistaken for Col-
orado squawfish less than 10 inches in
length.
Length at the end of the first year
averages 2.9 inches, 15.8 inches at 6 years,
and 24 inches at 11 years (Vanicek and
Kramer 1969). In the past, specimens
6 feet long and 80 pounds have been
reported although over the last decade
fish over 15 pounds and three feet long
have rarely been collected. (USFWS, in
preparation).
Range: Historically, the Colorado
squawfish was found throughout the Col-
orado River Drainage in mainstream
channels extending into Colorado in the
Green, Yampa, White, Colorado, Gun-
nison, Dolores and Animas rivers (Behnke
and Benson 1980). Current distribution in
Colorado is restricted to the lower reaches
of the Green, Yampa, White, Colorado and
Gunnison rivers (USFWS, in preparation).
Family Cyprinidae
The Colorado Squawfish is listed as a
federal and state endangered species.
Habitat: Adults are found in big, deep
water inhabiting eddies, pools, and other
areas adjacent to the main current flow,
moving into main channel areas to feed.
Young squawfish inhabit shallow, quiet
backwater areas off main river channels
(Haynes and Muth 1982).
Small invertebrates are the main source
of food during the first year of life, then
fish form an ever increasing portion of the
diet. By the time the squawfish attains a
length of 8 inches, fish make up the bulk
of the squawfish's diet (Behnke and Ben-
Geniis Pychocheilus
25 Colorado's Little Fish
Adult male speckled dace in breeding colors.
Adult Colorado squawfish.
Detail of head of the Colorado squawfish.