7719

• UCREFRP Catalog Number: 7719
• Author: Seethaler, K. H.
• Title: Resume of Current Knowledge on Colorado Squawfish.
• USFW Year: 1976.
• USFW - Doc Type: Logan, Utah.
• Copyright Material: NO

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I have not yet been able to determine what it is that provides
the impetus to migrate into the Yampa in the early summer. I
strongly suspect that the outward migration of late summer is
influenced by the drop in water level. The habitat is greatly reduced
at that time. Some deeper pools remain which might provide winter
habitat. Local fishermen have reported seeing them in these pools
under the ice. I tried to demonstrate that they could still be around

by setting nets earlier this month, but was unsuccessful.

Extensive seining for young fish by myself and McAda from Lily
Park to Horseshoe Bend below Vernal, Utah and at Grand Junction
produced only two juvenile squawfish. We captured them on October 3
of this year below the bridge at Je~sen, Utah in a backwater dominated
by large carp (Cyprinus carpio) and numerous Red shiners (Notropis
lutrensis). This is, I believe, the only such reporting since 1971
when Holden caught three juvenile squawfish in the Colorado around
Moab, Utah. This lack of success in finding young squawfish serves

to further document the drastic drop in reproductive success.
For the immediate future, I hope to complete my thesis by this
spring. I intend to compile all work to date, on this species as
well as relevant work on other species of squawfish. I will include
some background on its evolution and that of the Colorado River. I
will report on the field study. There will be a section on Age and

Growth from scale samples collected. This can be compared with

Vanicek's Age and Growth data. Genetic comparisons by enzyme
electrophoresis will be used to compare Yampa/Green River squawfish
with those found around Grand Junction. Samples of young squawfish