7125 ‎(2)‎

• UCREFRP Catalog Number: 7125
• Author: McAda, C. W.
• Title: Aspects of the Life History of Three Catostomids Native to the Upper Colorado River Basin.
• USFW Year: 1977.
• USFW - Doc Type: Utah State University,
• Copyright Material: YES

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during the entire year. Even though introduced fish composed the
majority of the catch in the gravel pit, the flannelmouth sucker was
still the most abundant species. Carp (Cyprinus carpio), green sunfish
(Lepomis cyaneZZus) and black bullheads (IctaZurus meZas) have become
well established and are almost as abundant as the ubiquitous
flannelmouth sucker.
Razorback suckers were less common in the Colorado River than
they were in the gravel pit. A sample taken by electrofishing in
the Colorado River in the spring of 1975 contained 127 flannelmouth
suckers, 109 bluehead suckers and 1 razorback sucker. Another
collection, at the mouth of the Gunnison River in April 1976, yielded
96 flannelmouth suckers, 86 bluehead suckers, and no razorback suckers.
Only a few razorback suckers were collected at other locations
in the basin (Table 6). A single razorback sucker (1% of the total
catch) was collected at Sand Wash, and two specimens (3.3% of the
total catch) were collected at Island Park in April, 1975. In
addition, a single razorback sucker was collected there the following
fall. None were collected at Horseshoe Bend or in the Yampa River
farther upstream than Box Elder Campground (Figure 2). The absence
of razorback suckers in collections from the upper Yamper River
(Table 3) probably indicated that they did not occupy this section
of river. However, this may not have been the case for Horseshoe
Bend, since only one collection was made at that location. A single
razorback sucker was taken by the Colorado River Fishes Recovery
Team just upstream from Horseshoe Bend in May 1976 [Personal
communication, K. H. Seethaler, Utah Cooperative Fishery Research
Unit, Logan]. Another specimen was caught by anglers in that area