6042

• UCREFRP Catalog Number: 6042
• Author: Haynes, C. M., R. T. Muth and T. P. Nesler.
• Title: Identification of Habitat Requirements and Limiting Factors For Colorado Squawfish and Humpback Chub.
• USFW Year: 1985.
• USFW - Doc Type: Fort Collins, Colorado.
• Copyright Material: NO

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Table 13. Die1 densities of drift-net-collected Colorado squawfish larvae
(numbers per 1,000 m3)a in the Yampa River, Colorado, Box
Elder site (river km 3.1), 1983. Blank spaces mean no catch.
Size ranges for developmental phases are cumulative for the
entire sampling season.
Date Sunrise Noon Sunset Midnight Day Night
Protolarvae (7.3-9.2 mm TL)
7/20-21 0.9 0.5
7/22-23 0.4 1.6 1.0
7/23-25 0.5 0.3
8/03-04 0.8 0.4 0.6
8/08-09 1.2 13.2 2.9 10.2 7.2 7.0
8/09-10 1.1 1.2 1.1
8/15-16 1.3 0.7
8/16-17 1.5 1.5 1.5
8/20-21 0.4 1.0 0.5 0.7 0.3
MEAN TOTAL 0.2 1.8 0.9 1.6 2.0 2.5
Meso1arvae (8.0-9.3 mm TL)
7/22-23 0.4 0.2
7/23-25 0.7 0.4
8/03-04
8/08-09 14.6 1.7 5.7 15.8 8.2 10.8
8/09-10 2.8 3.3 1.1 3.5 3.1 2.3
8/15-16
8/16-17 0.7 0.7 0.7
8/20-21 1.0 0.5
MEAN TOTAL 2.3 0.8 0.9 2.5 3.1 3.4
Combined larvae
7/20-21 0.9 0.5
7/22-23 0.8 1.6 1.2
7/23-25 0.7 0.5 0.4 0.3
8/03-04 0.8 0.4 0.6
8/08-09 15.8 14.3 8.6 26.0 15.4 17.3
8/09-10 2.8 3.3 2.2 4.7 3.1 3.5
8/15-16 1.3 0.7
8/16-17 2.2 2.2 2.2
8/20-21 0.4 2.0 0.5 1.2 0.3
MEAN TOTAL 2.3 2.4 1.7 3.8 4.7 5.6
aMean catch of three nets set for 1-2 hrs at each sampling time; day =
combined sunrise and noon samples, and night = combined sunset and
midnight samples