7144

• UCREFRP Catalog Number: 7144
• Author: Inslee, T. D.
• Title: Spawning and Hatching of the Razorback Sucker
• USFW Year: 1982
• USFW - Doc Type: Western Association of Fish & Game Agencies
• Copyright Material: NO

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stations, however, had very low densities of invertebrates (10 to 80
organisms per square foot). Pearson attributed these low densities
to the shifting sand substrate at the Ouray site.
BID/WEST, Inc., began sampling invertebrates quarterly, during
1978, at the Jensen U.S.G.S. gaging station near Split Mountain. Re-
sults to date have shown the Jensen station to have a high species
diversity. The dominant invertebrates at the site have been the
ephemeropterans, chironomids, and trichopterans (Holden and Crist
1978).
Plankton, Periphyton, and Macrophytes - Virtually no literature
exists which addresses the plankton, periphyton, and macrophytes of the
Green River. This is understandable in that these components of aquatic
systems are relatively rare in turbid rivers (Hynes 1970).

Field Study
Fishes - Over 22,000 fish, representing 18 species and one hybrid,
were caught during the study (Table 2). Eight of the species were na-
tive and 10 were introduced. The exotic red shiner comprised 63% of the
total catch and was the most abundant fish. Carp (Cyprinus carpio) and
fathead minnows (Pimephales promelas), also exotics, were commonly cap-
tured. These three species comprised nearly 7d% of the total catch.
The flannelmouth sucker (Catostomus latipinnis), bluehead sucker
(Pantosteus discobolus), and speckled dace (Rhinichthys osculus) were
the most common native species, although Colorado squawfish, especially
juveniles and young-of-the-year, were also quite common (Table 2). Six