7153

• UCREFRP Catalog Number: 7153
• Author: Holden, P. B.
• Title: Study of the Habitat Use and Movement of the Rare Fishes in the Green River, Utah.
• USFW Year: 1978.
• USFW - Doc Type: Logan, Utah.
• Copyright Material: NO

t-tOOC:(l
IQ18'

. I'" .,

Paul B. Holden
B IO/WEST, Inc.
P. O. Box 3226
Logan, UT 84321

I
i~/I'J--t

(

_ 07/Sj-r
)-/tJ / d~4(

/C1?~

A STUDY OF THE HABITAT USE AND MOVEMENT OF THE
RARE FISHES IN THE GREEN RIVER, UTAH

-1 i ::~
f ! J-~'

Paul B. Holden
BID/WEST, Inc.
Logan, Utah

Abstract. A study was conducted in the Green River of Utah to
determine habitat use and movements of the endangered Colorado
squawfish (Ptychocheilus lucius) and humpback chub (Gila cypha)
and the rare bony tail chub (Gila elegans) and razorback sucker
(Xyrauchen texanus). Backwaters with no current, a silt substrate
and over a foot of depth were preferred by young rare fishes; lar-
ger specimens used faster, deeper eddies and runs. A 2-1/2 day
study of movement of young-of-the-year Colorado squawfish was in-

conclusive but suggested little movement between a backwater and

the main river channel. Young-of-the-year razorback suckers were
tentatively identified and represent the first wild, young razor-

backs on record from the Upper Colorado Basin. Exotic species

were more common than native species in samples containing young

rare fi shes.

INTRODUCTION

The upper Colorado River basin contains two fishes presently
listed as endangered by the U. S. Fish and Wildlife Service, the
Colorado squawfish (Ptychocheilus lucius) and the humpback chub
(Gila cypha). Two other species, the bony tail chub (Gila elegans)
and the razorback sucker (Xyrauchen texanus), are also rare and

-r" 0 N~ \k. c:h ~ A'FS ,
I fl\NS ' I\:)()
\q,1> ... ~~-g, v

.