7321

• UCREFRP Catalog Number: 7321
• Author: U.S. Fish and Wildlife Service.
• Title: Fish and Wildlife Service Upper Colorado River Basin Technical Advisory Study Important Reach Analysis - CRFP.
• USFW Year: 1984.
• USFW - Doc Type: \
• Copyright Material: NO

COLORADO SQUAWFISH

Spawning Habitats

Assumptions :

1. Colorado squawfish utilize cobble substrate interspersed
with deep pools for spawning.

2. The presence of ripe female Colorado squawfish, several
adult-size fish greater than 450 mm during the spawning
season and larval squawfish less than 15 mm is adequate
evidence to confirm the presence of Colorado squawfish
spawning in the immedia te vicinity.

3. The presence of one or more adult size Colorado squawfish
greater than 450 mm during the spawning season and larvae
greater than 25 mm indicates an area of possible spawn~ng.

Classification: Confirmed spawning areas

Criteria

1. Occurrence of deep pools interspersed with cobble/riffle
habitat.

2. Collection of ripe adult Colorado squawfish or observation
of two or more radio-tagged adult Colorado squawfish migrating
to a common 5-mile reach during the suspected spawning season.
'-

3. Presence of larval Colorado squawfish less than 15 mm TL.

Classification: Suspected spawning areas

Criteria

1. One or more radio tagged Colorado squawfish migrating to
an area during the suspected spawning period.

2. Occurrence of larval Colorado squawfis less than 25 mm IL.

3. Occurrence of deep pools interspersed with cobble/riffle
habitat.

Data Sources;

CRFP data files and various reports, 1979-1984.

Archer, D. L. et a1. 1984. Colorado River fishes monitoring
project, second annual report. pp. 21-26.

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