7953

• UCREFRP Catalog Number: 7953
• Author: Miller, W. H., et al.
• Title: Colorado River Fisheries Investigations, 1979 Progress Report - Draft,.
• USFW Year: 1980.
• USFW - Doc Type: ‎(submitted in partial fulfillment of Contract No. 9-07-40l-1016 with the Water and Power Resources Service)‎,
• Copyright Material: NO

47
Habitat Preferences
Colorado Squawfish - Shoreline areas, eddies and runs produced most of
the adult squawfish captures while back-water areas produced the major
numbers of subadult and young_of_theyear squawfish.
i
Substrate type associated with fish collection were identified by visual
inspection. Although the more rough substrate types were difficult to
collect from, samples of fishes` indicated that adult Colorado squawfish
preferred habitats found over sand and silt. Juvenile squawfish appeared:
to select sand substrate and young-of-the-year fish were found mainly
over silt. Of course these substrate relations may be more a correlation
of habitat preferences than substrate selection because substrates are
4-
definitely influenced by water velocities.
Juvenile Colorado squawfish were captured predominantly at water
dgpths between 0.25 and 1.2 feet. Water velocities at capture sites
indicated that young-of-the-year squawfish preferred habitats witH
little or no current. Adult squawfish were found in-habitats that had
,water currents with velocities varying from 0.15 to 0.95 feet per second.
Juvenile squawfish were captured predominantly in habitats with little
(0.15 fps) or no water velocity.
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Anleffort was made in 1979 to explore the movement patterns of young-of-
the-year Colorado squawfish. Seven backwater areas were studied, of
which only three yielded squawfish. Samples taken in these three backwaters