9540

• UCREFRP Catalog Number: 9540
• Author: Christopherson, K., G. J. Birchell and T. Modde.
• Title: Larval Razorback Sucker and Bonytail Survival and Growth in the Presence of Nonnative Fish in the Stipprup Floodplain.
• USFW Year: 2004.
• USFW - Doc Type: Salt Lake City, UT.
• Copyright Material: NO

1
~ Table 1. Summary of larval razorback sucker, bonytail, and nonnative fish quantities
introduced into enclosures at The Stirrup floodplain wetland, Green River (RM
276.0) May 2002.

i
i
Number introduced
Low-density High-density
Species Date ~ enclosure enclosure Control
Razorback Sucker May 14, 2002 5,788 0 1,000
May 17, 2002 5,590 97,315 0
May 23, 2002 48,995 128,794 0
May 24, 2002 0 215,707 0
May 29, 2002 0 15,377 0
Total RZ 60,373 457,193 1,000
Bonytail May 8, 2002 21,250 71,500 5,250
Fathead Minnows May 17-24, 2002 a 75 81 0
Red shiners May 17-24, 2002 42 37 0
Black bullheads May 17-24, 2002 16 15 0
Green sunfish May 17-24, 2002 12 18 0
Carp May 17-24, 2002 4 3 0
Total Non-native 149 154 0
a Most nonnative fish were introduced on May 17, 2002. However, there were six black bullheads and
approximately 30 red shiners added to each enclosure on May 23, 2002. Twenty-five fathead minnows and 16 green
sunfish were added to the high-density enclosure on May 21 and May 24, 2002 respectively.
The densities for razorback sucker and bonytail were higher than may be naturally
expected, and were considered a positive control to evaluate if survival was possible at any
density. Larval razorback sucker were obtained from the Ouray National Fish Hatchery. A total
of 60,373 larval razorback suckers were introduced into the low-density enclosure and 457,193

into the high-density enclosure (Table 1). Only larval razorback sucker and bonytail were
5