7167

• UCREFRP Catalog Number: 7167
• Author: Miller, W. H., R. A. Valdez and P. G. Mangan.
• Title: Fisheries Investigations of the Upper Colorado River, Rifle to Debeque, Colorado.
• USFW Year: 1981.
• USFW - Doc Type: Salt Lake City, Utah.
• Copyright Material: YES

3.

Two razorback suckers were collected during the survey (Table 3).
Both fish were caught in the Parachute area within 3 miles of each
other. These new records extend the recorded upstream distribution of
the razorback sucker in the Colorado River. Both fish were in comparatively
good condition, lacking necrosis, fin deterioration, and parasite
infestation often associated with razorbacks caught in the Grand Junction
area. Though both fish were adults, determination of sex was difficult
because of a lack of spawning condition coloration or tuberculation.
Table 3. Habitat Parameters and Catch Information of Razorback
Suckers Captured Between Rifle and Debeque, Colorado,
July 14-16, 1981
Tag TL WT Depth Velocity Substrate
Common Name Number (mm) (g) Habitat (feet) (fps)
Razorback sucker 2587 471 1180 Shore 1.2 0.0 Silt
Razorback sucker 2529 524 1620 Main 6.0 1.4 Rubble
channel
Compared to other sampling sections on the Colorado River studied
by FWS over the past 2 years, the Rifle-Debeque section has a higher
number and diversity of sucker hybrids. Nine hybrid suckers were
captured representing four distinct crosses (Table 1). At this time we
do not have an explanation for the large number of hybrid suckers in this
river section.