7203

• UCREFRP Catalog Number: 7203
• Author: Osmundson, D. B. and L. R. Kaeding.
• Title: Colorado Squawfish and Razorback Sucker Grow-Out Pond Studies as Part of Conservation Measures for the Green Mountain and Ruedi Reservoir Water Sales
• USFW Year: 1989.
• USFW - Doc Type: Final Report.
• Copyright Material: NO

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with that of squawfish at 13th Hole or Humphrey ponds (Fig. 6). The
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forage, coupled with high endoparasite loads
(see below), probably accounts for slow growth and low condition.
Sexual Maturity
Two of 15 squawfish collected on 30 May 1989 were highly tuberculated and
had enlarged genital papillae; one fish was 263 mm long and weighed 111 g;
the other was 260 mm TL and weighed 131 g. Seethaler (1978) examined 147
preserved Colorado squawfish, 184-652 mm long, for evidence of sexual
maturity; all those > 503 mm TL were mature; the smallest mature fish was
428 mm TL. Seethaler concluded that Colorado squawfish do not mature

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until they exceed 400 mm TL and six years of age. Tyus et al. (1987)
captured 160 squawfish in "breeding condition" (i.e., tuberculated) from
the Green and Yampa rivers during 1981-85; the smallest male was 465 mm
TL; the smallest female, 507 mm TL. Squawfish raised at Dexter NFH ma-
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1986 1987 1988 1989
FISH CHALET -h- WEST --*- 13TH HOLE HUMPHREY
Figure 6. Change in mean body condition of Colorado squawfish in Fish
Chalet (FC), West (WS), 13th Hole (13) and Humphrey (HU) ponds, 1986-89.
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