3022

• UCREFRP Catalog Number: 3022
• Author: Berry, C. R. and R. Pimentel
• Title: Swimming Performances of Three Rare Colorado River Fishes
• USFW Year: 1985
• USFW - Doc Type: Transactions of the American Fisheries Society
• Copyright Material: YES

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Transactions of the American Fisheries Society 114:397-402, 1985
@ Copyright by the American Fisheries Society 1985

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Swimming Performances of 1fhree Rare Colorado River Fishes

CHARLES R. BERRY, IR. AND RICHARD PIMENTEL

Utah Cooperative Fishery Research Unit
Utah State University, Logan, Utah 84322

Abstract

A stamina tunnel was used to determine the prolonged swimming performance of age-O hump-
back chubs Gila cypha, bonytail chubs G. elegans, and Colorado squawfish Ptychocheilus lucius
and of subadult Colorado squawfish. The "fatigue velocity" in body lengths per second at which
50% of the test fish were fatigued (FV50) waS determined at 14, 20, and 26"C. The ranges ofFV50
values for the three fishes (average total length in parentheses) were: humpback chubs (95 mm),
4.4-5.7; bonytail chubs (99 mm), 4.7-5.8; small Colorado squawfish (104 mm), 4.0-4.5; large
Colorado squawfish (432 mm), 2.0-2.3. Abs~lute speed oflarge Colorado squawfish was about 2.4
times that of small Colorado squawfish. SWimming ability of the subyearlings increased with
increased water temperature. These rare fisb. had prolonged-swimming abilities similar to other
fish species.

Received May 29,1984 Accepted March 2, 1985

The Colorado squawflsh Ftychocheilus lucius,
humpback chub Gila cypha, and bonytai1 chub
G. elegans are endemic fishes of the Colorado
River system that are threatened with extinction.
Major causes of their decline are habitat modi-
fication caused by dams, water depletion, and
introduction of exotic species (Hickman 198B).
Although the biology and habitat preferences iof
these fishes have become better understood in
recent years (Holden and Wick 1982; Valdez and
Clemmer 1982), there is still a great need for
biological data that can be used in planning and
designing water development projects. This need
has been addressed by recent field studies (Kaed-
ing and Zimmerman 1983; Tyus et al. 198'i1),
laboratory studies (Pimentel and Bulkley 19~3;
Berry 1984), and symposia (Miller et al. 1982;
Adams and Lamarra 1983). However, there have
been no studies ofthe swimming abilities oftheise
species. Such information is needed for the prop-
er design of fish ladders (Boyer 1961; Collins ,et
aI. 1962; Slatick 1971), culverts (Jones et aI. 1974),
and water intakes (Dom et aI. 1979; Hettler 197~).
Substantia11iterature exists on the swimmi~g
performance of many fishes (Beamish 1978), but
the use of these data to predict the capabilities
of unstudied species may be questionable. The
objective of the present study was to determine
the endurance of three rare fishes at pro10ng~d
swimming speeds. Prolonged swimming speeds
are those that a fish can maintain for 15 s to 200
min, rather than burst speeds or speeds that can
be sustained indefinitely (Webb 1975). We at-

tempted to reproduce sudden velocity increases
that might be encountered by a fish entering a
culvert or fish ladder.

Methods
All fish were hatched and reared at Willow
Beach (Arizona) National Fish Hatchery except
for the bonytai1 chubs, which were reared at Dex-
ter (New Mexico) National Fish Hatchery. Fish
were transported to the Utah Water Research
Laboratory, Logan, Utah, where they were held
in circular tanks in which there were no appre-
ciable water currents. The photoperiod was 14 h
light: 10 h darkness and fish fed on commercial
trout pellets ad libitum twice daily. Water quality
in each tank was controlled, so that dissolved
oxygen concentrations were 90-100% of satu-
ration, pH was about 8.0, and ammonia re-
mained below 0.2 mglL. Temperature acclima-
tion to 14, 20, and 260C followed procedures
recommended by Richards et aI. (1977); fish were
held at acclimation temperatures for at least 1
week before tests.
Fish were grouped for testing according to
species and tota11ength. Colorado squawflsh were
divided into groups oflarge (375-491 mm) and
small (78-138 mm) fish. Humpback chubs were
87-107 mm; the bonytai1 chubs 90-107 mm. Sex
of tested individuals was not determined, but
because all fish were subadults, sex probably did
not affect swimming performance (Brett 1965).
Swimming performance was determined in a
stamina tunnel similar to that described by

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