7048

• UCREFRP Catalog Number: 7048
• Author: Desert Fishes Council ‎(Edwin Pister, e.
• Title: Proceedings of the Desert Fishes Council
• USFW Year: 1991.
• USFW - Doc Type: Volumes XX and XXI
• Copyright Material: NO

WINTERTIME MOVEMM AND HABITAT OF ADULT
COLORADO SQEMNFISH AND RAZORBACK SUCKERS
IN THE GREEN RIVER
by
R.A. Valdez and W.J. Masslich
BIO/WEST, Inc.
1063 W. 1400 N.
Logan, UT 84321
Wintertime movement and habitat of adult Colorado squawfish (Ptychocheilus
lucius) and razorback suckers (Xyrauchen texanus) were assessed for the first
time in the Green River with the aid of radiotelemetry. Twenty individuals of
each of these rare, endemic species were tracked and monitored from December 1
to March 31, 1986-87 and 1987-88, in a '97-mile reach from Echo Park, CO
downstream to Ouray, UT. This investigation revealed that adult Colorado
squawfish and razorback suckers overwinter in specific river regions, generally
less than 3 miles long. Although one Colorado squawfish ranged 25.9 miles, and
one razorback sucker ranged 10.5 miles, 72% of all the radiotagged fish
remained within a 3-mile reach during the 4 winter months. This study also
showed that these fishes may remain for days in a 100-m diameter. area within
slackwaters, slow runs, eddies, or backwaters. The fish move periodically to
one of several "favorite spots" or microhabitats, characterized by greater
than average depth and low velocity. The position of each fish is often
associated. with underwater structure such as sand shoals, sand ridges, or
cobble jetties.
Movimiento y habitat de adultos del Colorado squawfish (Ptychocheilus
lucius) y razorback sucker (Xyrauchen texanus) fueron avaluado durante el
invierno por la primera vez en le Rio Verde con use de radiotelemetria. Veinte
individos de cada de estos especies raros y endemicos fueron rastreados de
Deciembre 1 a Marzo 31, el los anon 1986-87 y 1987-88, en una region de 97
millas de Echo Park, CO a Ouray, UT. Esta investigacion revelado que los
adultos del. Colorado squawfish y razorback sucker pasan el invierno en regiones
especificas, generalmente menos de 3 millas distancia. Aunque un Colorado
squawfish tuvo un alcance de 25.9 millas, y un razorback sucker de 10.5 millas,
72% de todos los peces de radiotelemtria se quedaron dentro de una region de 3
millas durante los 4 meses del invierno. Este estudio tambien ensenio que
estos peces pueden quedarse por dias en un area de 100 m en diametro entre
habitats especificas; "slackwaters, slow runs, eddies, o backwaters". Los
peces se mueven periodicamente a una de varias localidades o microhabitats,
caracterizadas por mas que promedio de profundidad y velocidad minima. La
posicion de cada pez frecuentemente fue asociada con estructura, como bajos y
espinazos de arena, o puntas rocosas.
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