6025

• UCREFRP Catalog Number: 6025
• Author: Kaeding, L. R. and D. B. Osmundson.
• Title: Report on the Studies of the Endangered Fishes of the Upper Colorado River As Part of Conservation Measures for the Green Mountain and Ruedi Reservoir Water Sales
• USFW Year: 1988.
• USFW - Doc Type: Second Annual Progress Report.
• Copyright Material: NO

Table 3. Data for larval Colorado squawfish collected in 1986 and 1987.
Estimated Estimated Estimated
Collection TL Age Hatching Spawning
Locationa
-------------- Date
-------------- (mm)
-------- (days)
------------ Date
------------- Date
------------
1986
CO RM 158.1 Aug 21 9.2 12.1 Aug 9 Aug 5
10.1 15.1 Aug 6 Aug 2
11.8 19.1 Aug 2 Jul 29
13.8 21.8 Jul 30 Jul 26
CO RM 158.1 Aug 28 11.5 18.5 Aug 9 Aug 5
CO RM 163.7 Aug 28 12.4 20.1 Aug 8 Aug 4
12.8 20.6 Aug 7 Aug 3
14.8 22.7 Aug 5 Aug 1
GU RM 2.6 Aug 28 14.6 22.5 Aug 5 Aug 1
1987
CO RIM 162.7 Jul 30 14.3 22.3 Jul 8 Jul 4
- - ----- ----------------- - -- - - - -----
aCO = Colorado River; GU = Gunnison River
downstream from the most upstream collection site for larval Colorado
squawfish (RM 163.7; Fig. 3). Mean catch per effort for Colorado squawfish
larvae within the 18-mile reach was 4.02/100 m2 (SD = 7.87; Table 4). Mean
total length of these fish was 24.7 mm (SD = 3.14; Table 5); estimated post-
hatching age (based on back calculation of larvae) was 53-63 days.
1987
No squawfish larvae were found within the 15-mile reach in 1987, nor were
any collected from the lower Gunnison River. Only one larval squawfish was
12