Swimming Performances of Three Rare Colorado River Fishes
Utah Cooperative Fishery Research UnU
Utah State University. Logan, Utah 84322
A Btamina tunnel wan u d to determine the prolonged swimming parformanca of age-0 hump
back chubs Gila cypha,bonyttul chuh G. ekgans, and Colorado squawfmh Plychochdus /ucius
and of aubadult Colorado tqunwfiah. The "fhtigue velocity" in body lengths par ~acondat which
50% of tha test fish were fatigued (FV50)war datemind at 14,20, and 2 6 T . Ths ranem of W S O
valw for thc t h m 0mhm (average total length in paranthascs) were: humpbeoL chub (95 mm),
4.4-5.7; bonytail chubs (99 mm), 4.7-5.8; smnll Colorado squrHBah (104 mm), 4.M.5; huge
Colorado quawiltah (432 mm), 2.0-2.3: Absolute spstd of large Colorado sqwwflnhwarn about 2.4
timas that of amall Colorado sgmwlish. Swimming ability of the subyearincmmul with
i n c d water ttmpcmtm. Thew rare flah had prolonged-umimnhg abilities similar to other
Acaptod March 2, 1985
The Colorado squawfish Ptychocheilus luciup, temptad to reproduca sudden velocity incremes
humpback chub Gila cypha, and bonytail chub that might be encountemd by a fiah entoring a
G. elegans are endemic fishes of the Colorado culvert or fish ladder.
River system that are threatmad with extinction.
Methods
Major causes of their decline arc habitat modiAll fish were hatched and reared at Willow
fication caused by dams, water depletion, and
introduction of exotic species (Hiclunan 1983). h c h (Arizona) National Fiah Hatchery except
Although the biology and habitat preferencas of for the bonytail chubs, which were reared at Dexthasa fishca have become better understood in ter (New Mexico) National Fish Hatchery. Fish
recant yeam (Holden and Wick 1982;Valdez and wcre transportad to the Utah Water Research
Clcmmer 1982), there is d
l a great need for Laboratory, Logan, Utah,where they wcre held
biological data that can be used in planning and in circular tanka in which there were no apprtdesigning water development projects. This need ciable water current8. The photopariod was 14 h
has been addressed by recent field studits (Kaed- light : 10 h darkness and h h fed on commercial
ing and Zimmennan 1983; Tyus at al. 1984), trout pellets ad libitum twice daily. Water quality
laboratory *dies (Pimentcl and Bulkley 1983; in each tank was controlled, so that dissolved
Berry 1984), and symposia (Miller et al. 1982; oxygen concentrations were 90-100% of aatuAdams and Lamarra 1983). However, there have ration, pH waa about 8.0, and ammonia rsk e n no studies of the swimming abilities of these mained below 0.2 m a . Tempratwe acclimaspecies. Such information ia needed for the prop- tion to 14, 20, and 26°C followad procedures
er design of fish ladders (Boyer 1961; Collins et recommended by Richarda et aL (1977); fish were
al. 1962; Slatick 197l), culverts (Jones et al. 1974), held at acclimation temperaturaa for at leaat 1
and water intakes wrnat al. 1979;Hettler 1979). week before tests.
Fish were groupad for testing according to
Substantial literature exists on the swimming
performance of many fishes (Baamish 1978), but spbcia and t g l . Colorado squadah were
the use of thesa data to predict the capabilities divided into grouga of large (375-491 mrn) and
of unstudied species may be questionable. The small (78-138 mm) fish. Humpback chubs were
objective of the present study was to determine 87-1 07 mm; the bonytail chubs 90-107 mm. Sex
the endurance of three rare fishm at prolonged of tested individuals waa nbt determined, but
swimming speeds. Prolonged swimming epee& because all fish were subadults, sex probably did
arc thorn that a fish can maintain for 15 s to 200 not affect swimming performanca (Brett 1965).
Swimming performance was determined in a
min, rather than burst speeds or s w s that can
be sustained indehitely (Webb 1975). We at- stamina tunnel similar to that described by
the-year trout to mature trout and groundwater.
Transactiom of the American Fishmias Sociaty
94:32-39.
NORTHCOTB,
T.0.1962. Migratory behavior of juvenile rainbow trout, Salmo galrdnerl, in outlet
and inlet shwms of Lnon Lake, British Columbia
Journal of the Fisheries Remarch Board of Canada
19:201-270.
NORTHCOTB,
T. 0. 1969a. -Lakeward migration of
young rainbow trout (Salmogairdnm') in the u p
per Lardaau River, British Columbia Journal of
the Fishmiae Rasaarch Board of Canada 26:3345.
NORTI-ICU~E,
T.0.1969b. Pattams and mechmi8ms
in lakcward migratory behavior of juvenile trout.
Pagas 183-203 in T. O. Northcote, editor. Sympodurn on salmon and trout sacama. H. R.
MacMillan L4Cturae in Fisheries. University of
British Columbia, Vancouvar, Canada.
R ~ ~ ~ TT.
I E 1977.
,
Effect of density on growth and
Burviva1 of rainbow trout. Aquaculture 11929334.
RICKER,
W.E. 1946. Production and utilization of
Bah populations. Ecolo@cal Monographs 16:374391.
SAUN~ERS, R. L., AND E. B. HENDHR~ON. 1970. Ill-
fluenc? of photopariod on m o l t davalopmant and
p w t h of Atlantic aalmon (Sdmosolar). Journal
of the Fieherim Research BoPrd of Chmda 27:
l29%13ll.
SIANEY,P.A.,ANDT. G.NORTHCOTE.1974. Effm
of prey abundance on density and territorial & ,
hnvior of young rainbow trout (Salrno gdrdneri)
in laboratory stream channels. Journal of tha El&.
trim Rasaarch Board of Canada 3 1:1201-1 209.
SOMMON,
D. J., AND D.PATERSON.1980. I d u e n m
of natural and rogulntcd straam flow on aurvival
of brown trout (Salmo tnrtta L.) in a chnlkstrcaul.
Environmental Biology of Fishee 5379-382.
SPIBWI,R E. 1979. Me1 rhythms of circulating prohcdn, corthl, thyroxint, ~d triidothyronine
levela in fishes: a review. Revue Canadienne da
Biologia 38:301-3 15.
WWITE,R. J. 1973. Straam channel suitability for
coldwatar 6th.hocaadings of the Annual Mtttitq
of tha Soil Conearvation Society of America 28:
61-79.
Zuq J. H. 1974. Biostalistical analysis. Rantica-Hall,
En@awcd Cliffs,NJ, USA.
ZrPm, C. 1956. An evaluation of tha ramoval mathod of &adng
animal populations. Biomatnlca
12:163-189.
398
BERRY AND PIMENTEL
TABLE
I.-Swimming pe@ormance of three Colorado River fihes. Swimmlng veIoca& a! 2 and 120 min
Lq
expremd as body lengths (BL) get second at which 50% qfthefrsh werefatigued (FV50) and its equivalent
absolute swimming speed; the 95% corlfrdence interval is in parentheses.
2 mln
Number
of
v e l d t i m Numbm
tested
of Flnh
-
FV50
fEUd
Almoluta a-
(cdd
-
a MY
40%of the f~ahware faalpu4d In 2 m* rt the bighorn v a l d t y teatsd (5.7 BUa).
Thomas et al. (1964). The apparatus consisted
of two 500-L reservoire connected by two pipes.
a return-flow pipe, and the swimming chambcr,
a plexiglas tube 2 m long nnd 20 cm in diameter.
Blocking forces (Webb 1975) were probably insignificant becaust the largest Colorado squawfish's cross-sectional diameter was 9.9% of the
diameter of the tunnel. An electroma~eticcurrent meter recorded flow velocities, and a downstream barrier was elactri0ed with 5-10-V alternating current to encourage tiring individuals to
swim. The tunnel was wrapped with black pladc
at the upstream end to isolate the fish but to allow
the entrance of light from above.
A standard testing protocol was used. The apparatus was filled with water at the acclimation
temperature of the 0eh. One large or two small
fish were acclimated to the tunnel for 5 min at
a water velocity of 15 crnls. Preliminary tests
indicatd no difference in prolonged swimming
performance between fish acclirqated for 5 and
20 rnin. Fish that did not swim in the tunnel
during the acclimation period were excluded from
the tests. AAer the acclimatiop period, fish were
rapidly subjected to a selectad test velocity when
a stop-door was removed at the rear of the tunnel. An observer shocked tiring fish a8 needed
and recordad the time when fieh became impinged on the electrified scmn as the fatigue
time. Tests continued for a chosen period of 120
min or until fish fatigued.
Tcata with two to four 0ah were k t conducted
at selectad velocities to h d a range over which
the percent of fit& fatigued at 2 and 120 min
varied from 100% to 0%, respectively. Than, at
selecttd &xed velocides within the range, sample
size was increased to 9-14 small fieh or 4-6 k g 6
fish, deptnding on the numbar available. Tested
fish were measured, returned to holding tanks,
and monitored for mortality. Tested fish were
not r e d .
The method used for estimating swimming
ability was basically that d by Brett (1967):
the fatigue times of individuals in a group were
determined at a constant water velocity. Analysis
of covariance (covariate equals fish length) ww
usad to evaluate the effects of water temperature
and velocity on fatigue times. We used a "do*
msponw'' curve to characterize the relation between velocity and percent fatigued. The curve
was plotted as straight-line connections of threepoint moving averages. Tha FVSO (velocity at
which half the fish fatigued) at 2 and 120 ruin
was detarmined algebraically by linear interpo-
VCLOCITY ( c m l ~ w n d l
40
HUMPBACK
CHUB
M
'
P
.
m
to
P
'
m
Q
SMALL SQUAWFlSH
IP
M
40-
L
--
Fmum 1.-Relolion between percentage offaiguedfirh and water velocity at 14, 20, and 2BC for three species
of rare Colorado River-*ha. Points on lines (open symbob) are the moving averages of three experlrnentql
dda poinrs (solid symbols). The 120-min FVSO, or velocity at which 50% of thefih were fatigued in 120 min,
is shown with 95% corlfidencc intervals. The values on the upper velocity a.h are bared on the average length
qfallfirh tested In each group.
lation (Thompson 1947).Standard deviationsand
the t statistic were usad to form 95% confidence
intervals.
The 2-min W 5 0 values for each teat group
were slightly larger than the 120-min values (Table l), hdings that agr& with Brett's (1967) data
for sockeye salmon Oncorhynchus nerka. As expected, the FV50 values in body lengths/s for
largc Colorado squawfish were lower than those
for small ones, but when expressed in absolute
speeds, the fish-length-speed relation was positive. The humpback and bonytail chubs par-
formed similarly and had higher FV50 values
than Colorado ~quawfiahof about the same size.
Analysia of variance showed that water vclocity signi6cantly affactad the mean fatigue time
for all species (P < 0.0 1). Fish-length rangee covered 116 mm for large Colorado w u a d s h and
only 17-60 mm for other groups, but these diffcrencas had no significant effect on fatigue time
(P> 0.01).
Temperature significantly affected the ptrformana of db h (anal* of covariance, P <
0.01), but not of large fish. Increasing temperatures usually reveal some optimum at which the
gwimming ability of fish is maximum (Brett et
.,' I
TABLH
2.-Prolonged swimming pedormance of several freshwater f i r h a expressed ar M y length (BLJ per
second and its eguivalent absolute swimming sped.
,,?!
:.;:
,
I
.i
,>
Total length
Spia
A t h t i c ulmon
Salmo s a h r
T a p -
Prolo~rpesd
aturc
-,
M
BUn
omh
Souma
23
15
2.1-3.2
50-76
Kutty and bun@#
(1 973)
6-9
20
4.6-5.4
3141
Brett st al. (1958)
6
20
4.1-7.1
25-43
Butler md Millom*n (1971)
(a)
:,:.!
> ,,%'I.
. I:+ .
... X:, ,
/
;
<
j$,
Coho d m o n
Oncorhynchur krnctch
Rainbow trout
Salmo gairdnml
al. 1958). Ow data for the humpback and bonytail chubs arc consistent with this generalization
(Fig. 1). The mall Colorado squawfish parformed better at 26T than at 20°C, but their
inkmediate parfomance at 1 4 T confounded
the trend.Large Colorado equaw0sh did not improve performance with increase in temperature-an unexpected result that may have bean
related to the small sample size or to the possible
inaccuracy of estimates made without fatigue data
betwaan 0 and 100% (Stephan 1977).
We noticed p a t variation among individuals
in awimrning ability, aqmdally at intcmedia~
velocities. Such variability has been noted by
others (McNoish and Hatch 1978; Kovacs and
Leduc 1982) and probably represents different
levels of motivation, stress, and ability within
each species.
Dlecmrsion
These rare Colorado River fishes have biological traits that may confer survival advantages
in swift, sometime8 turbulent waters (Minckley
1973). The narrow caudal peduncle and high aspect ratio (square of the maximum fin height
divided by the fin area) of the caudal fin of the
humpback and bonytail chubs suggest suprior
swimming ability compared with that of other
species (Lighthill 1969). Although the ability of
thew two species was grater than that of the
Colorado squawfah of similar size, their prolonged swimming performance. at 20°C was similar to that of some other fishes (Table 2). A
downward bias to our dqta may have resulted
from the usu of unexarcised fish (Webb 1975)
and &om our use of a sudden velocity inmcaae,
instead of the gradually increasingvelocities usad
in other testa.
The h a 1 tempmature preferendurn for theta
.
speciea is 2625°C (Bulkley et al. 1981). It is
'
generally assumed that the final preferendurn is
the optimum temperature for moat physiological
functions of fish. Hence, the swimming performance of these sptcies at 2 6 T was probably new
maximum, although this conclusion is speculative becauao stamina was not evaluated at higher
temptraturaa. Maximum prolonged swimming
of other eurythermal specits usually occum at
temptraturcs between 25 and 30°C (Beamhh
1978).
Hydroelectric plants and other industrial complexes remove water at Btrvctures that are potential sitea for entrainment and impingement of
young fish. Rbcommended approach and screenface velocities at intakes art about 15 cmh
(Elamas 1976). The 120-min FV50 for small fish
exceeded 35 cmle at all ternpcraturas; consequently tho fish tested in our study should be
able to avoid entrainment. However, larvae may
be the most vu4mnble Life stage, m d there is no
publishad information on their swimming abil- .
ity.
Fi~h
passage must be provided to preserve migrating species such as the potarnodrornous Colorado squadsh, which undertakes epawning
migrations of several hundred kilometres (Tyus
1983). Fish laddm have been suggestad as a possible conservation maasure because the noahern
squadsh Ptychocheilur oregonenris readily uses
fish ladders on the Columbia River (Clay 1961;
SWIMMING
PERFORMANCES OF RARE COLORAW RWEFI FISHES
401
don to swimming spcad and temptraturn. CanaZimmer and Broughton 1965). Our data 8hould
dim Journal of ZOO~UW
49: 1221-1 228.
partially define one of a dozen biological criteria
B
m
m
,
F.
W. W. 1978. Swimming cspadty. Pago8
needad to design an expcrlmental fish ladder
101-187 in W. S. Hoar and D. J. Randall,editors.
(Trueba and Drooker 1982). Additionally, data
Fish physiology, volume VII. Locomodon. Acasuch as ours are required in formulas u d to
demic F'maa, New York, NY,USA
design culverts for 0Bb passago (Watts 1974; Ev- BERRY,C. R. 1984. Hematology of four rarc Colorado
River frahtr. Copda l984:79&793.
m u and Johnston 1980).
s@
of immature
We a m p t a d to simulate conditions that these BOYER,H. C. 1961. SwimAtlantic herring with rafemnce to the Passamafish might encounter after hydrolo& alterations
quoddy tidul projact. Transactions of the Ameriin sthabitat; however, our data arc incomcan Fiuherlts Society 90:21-26.
plete for moat engineeringand construction plan- BREYT,J, R. 1965. Tha mladon of uiza to rate of
ning. Many other a s p t s of the swimming peroxygen wmurnption and sustainad swimming
upacd of aockeye d o n (Oncorhynchus nerka).
formance and behavior of each lifa stage must
Journal of the Finharim Rasearch Board of Canada
be examined before developem can adequately
22:1491-1501.
considar fish preferences. Our data am probably
conservativebecaw of the limitations of the ted B m , J. R. 1967. Swimming performance of m k eye d m o n (Oncorhynchw rtcrka) in relation to
apparam and the UEC of unexercised fiah. The
fk-o
dme and ttmparatura. Journal of the Fisheffect of fish length, water velocity, and water
arias Rcaemb Board of Canada 24: 1731-1 741.
temperature on wrimming ability could hava been BREIT, J. R., H. H o m ~ r w AND
,
F. O. ALDERDICE..
1958. The effect of tornpsmtum on the cruising
prtdictad h r n cxietingliterature (&amish 1978).
spaad of ~ o u n g
sockeye qnd mho salmon. Jouraal
Unique to our study was the opportunity to evdof the Mahariee Rasaarch Board of Canada 15:
uate the qxci6c abilities of thoaa rare fiahea and
587405.
the finding that their abilities ware similar to BULKLBY,R V., C. BERRY,R PIMBNIEL,AND T.
those of other fishes of aimilar size. Thia is enBLACK. 1981. Toleranca and p m f e m m of Colcouraging bacause existing data for other species
orado River endangad fishes to salactad habitat
paramatcra. Utah Cooparadve Fiuhary Remarch
can augment our data in solving hh-pasmge and
Unit. Final Campladon Report, Utah State Unientrainment problems.
vanity, Logan,UT,USA
BUTLER,J. A., AND R E. W A1971.
NJ3kt
. of
Acknowledgments
the "salmon poisoninf tramatode Nunophyctus
Fun& for this work were provided by the U.S.
salmincola on t4e swimming ability of juvanile
Fiah and Wildlife Sarvia Colorado River Fishmalmonid 5mhce. J o d of ParauiMlogy 57:86&
865.
ery Project a d the Burtau of Reclamation. R.
Bulkley, L. Kaading, and H. Tyw reviewed an CLAY, C. H. 1961. Dcsi* of flshwaye and other fib
ftlcilldts. Dapnrtment of Hshcrh of Canada, Otearly draft of this paper, A. Burgess and J. Kehoa
taw, Canadn.
conducted most of the swimming teste. This & L U
N~.O.B.,J.RGAULBY,ANDCH.~
1962.
O.
project was administed by the Utah CooperAbility of snlmonida to a~ccndhigJ~fiah~ays.
ative Fishery Reeaarch Unit, which is jointly
Transactionr of the Amorimn Fiaheriea Society
91:l-7.
sponsored by the U.S.Fish and Wildlife Sarvice,
the Utah Division of Wildlife Resoruccs, and DORN, P., L JOHNSON, AND C. DARBY.1979. The
1yWimmin6ptrformanm of nine apacias of camUtah State University.
References
ADAMS,B. D., AND V. A. LAMARRA, aditom. 1983.
Aquadc rwouraa management of tht Colorado
River acosystcm.
Arbor Science, Ann Arbor,
MI, USA.
BARNES,D. 1976. hvelopmtnt document for best
ttchnology available far the location,deuign, canatruction, and capacity of coowater intake
structures for minimiziq adverse environmental
impact. US. Environmental Protodon Agency
440/176/015a, Washington, DC,USA.
BENANH,F. W. H. 1970. Oxygen consumption of
largemouth bass, Mlcropterus salmoides, h rela-
mon California inahom fishes. Transactions of
Amarican Fieherlea Sodety 108366-372.
EVANS,W. A, AND B. J O H N ~ O1980.
N . F i b mipration and fisb p-:
a practicnl guide to sol*
A& p ~ w
problems. U.S. IXpartmant of Agrlculture, For& Sanicc, EM 7100-2, Washington,
JX,USA.
Hmm.m, W . F. 1979. Swimspbadr of j u v d e
astuarine firh in a circular flume. Procatdinpa of
the Annual Confmnca Southtaatarn Association
of Pirh and Wildlift Agancies 31392-398.
HICKMAN,
T. J. 1983. Effact8 of habitat alterations
by antr& rwourcc davelopern in the uppar Colorado River Basin on endangered fiahan. Papa
537-550 in V. D. Adams and V. A. L
.cd-
402
BERRY AND
MCCAULHY.1977. Tarnpprature pmfbmncc stud.
itom. Aquadc rceourcte managamant of the Colim in environmantnl impact aasesrmanta: an overorado River ecosystem. Ann Arbor Science. Ann
view with procadural recommandations. J o u m
Arbor, MI, USA.
of thc Fieheria Raaaarch Board of Canada 34:
HOWKN,P. B., AND E. J. WICK. 1982. Life history
728-761.
and prosptcta for m v a r y of tha Colorado quawE. 1971. F h a g e of adult aalmon and trout
flah. Pwcs 98-108 In W. H. Millar, H. M. Tyus, SLATICH,
through an inclined pipe. Tranmactione of tho
and C. A. Carlson, oditors. Fiahts of the uppcr
American Fisheries Society 100:448455.
Colorado River &yarn:grtatnt and futura. Weatem Division, American Fiaherien Society, Bcthw- STEPW, C. E. 1977. Mathods for calculathg an
LC50. Pmgm 45-84 in F.L. Mnycr and J. L Hams
da, MD, USA.
link, aditom. Aquatic toxicology and hazard evalJONES, D. R., J. W. K~CENIUK,
AND 0.S. BMORD.
uation. Ammican Sodety of Tasting Mntarials,
1974. Evaluation of the uwimming parformancc
W 6 3 4 , Philadelphia, PA, USA.
of several fish epccim h r n the Mhckenzia River.
A. E., R. E. BURROWE,
AND H.H. CH
N
I+
Journal of the Fiaherla Reaaarch Board of Canada THOMAS,
WITH. 1964. A devica for Btamina rneasuremant
31:1641-1647.
of h a r l i n g salmonida. U.S. Fish and Wildlifa
I ~ w I NL
~R
, .,AND M. A. ZIMMERMAN.
1983. Lift
Strvicc R m b Report 67.
history and ecology of the humpback chub in the
, R 1947. Use of moving averago8and
Little Colorado and Colorado rivere af tha Grand T n o m ~W.
intarpolation to tstimata madian-effective done.
Canyon. Traneactions of the Amedcnn Fisheria
Bactariolugid Reviews 11: 115-145.
Society 112:577-594.
J., AND M. DROOKER.
1982. Modular inKOVA~J,
T. O., AND O. LWUC. 1982. Sublathal tox- TRUEBE,
novations in upetraam 6nh passape. U.S.Departicity of cyanide to rainbow trout (Salma gairdment
of
Enerpy,
DOE/ID/l2207-T2
mri) at difFamnt tarnparaturus. Canadian Joumal
(DE82010268), W d m g t o n , DC,USA
of Fiaherim and Aquatic Scitncas 39:1389-1395.
K u m , M. N., AND R. L. SAUNDERS.
1973. Swim- TYUS,H. 1983. Lonu of stream passa~eas a factor in
tho d a c h a of tha endangered Colorado aqunwfiah.
performatlct of young Atlantic d m o n (SalPwea 138-144 in R. Comer, editor. Issue8 and
mo salar) sa a&ted by d u d ambient oxygen
tachnology in tha m m g m c n t of importad westconcentration. Journal of the F~heriauReaaarch
am wildlife. Thome Ecological Instituta, TwhniBoard of Canada 30:223-227.
cal Bullatin 14, Boulder, CO,USA.
LAFUMORE,
R. W., AND M. J. D m . 1968. Effccta
of tarnperature acclimation on tha ewimming abil- Tws, H.M.,B. D. BURDICK,AND C. MCADh 1984.
Usa of radiotclematry for obtaining habitat prafity of amdmoutb baes fry. Tranmciions of tha
emnw data on Colorado squadah. North AmarAmerican Fisherion Socicty 97:17S184.
ican Journal of Fisharias Managemant 4: 177-1 80.
LIOHTHJLL,
M.J. 1969. Hydrodynamics of aquatic
R A., AND 0.H. CLaMMaR. 1982. Llfc bb
animal propulsion. Annual Raviaw of Fluid Ma- VALDH~,
tory and prospects for racovary of tha humpback
chap~cs1:413-446.
and bonytailchub. P w 109-1 19 in W. H. Millar,
1978. Stamina
MCNEISH,J. D., AND R. W. HATCH.
H. M. Tyua, and C. A. Carhn, editom. F i h of
tunnel tests on hatchery-reared Atlantic W o n .
the uppar Colorado River syetcm: praeant and fbProgressive Fish-Culturiat 40: 116-1 17.
turc. Wtatem Division, American Fisharies SoMILLBR,W. H., H. M. TYUS,AND C. A. CAR~SON,
ciety, Bcthasda. MD,USA.
editors. 1982. Fiahta of the upper Colorado River aystam: prweent and futuc. Wentern Division, WATTS.F. 1974. Dasign of culvert 0ahways. Watar
R ~ u r c aRaeaarch
s
Institute,Universityof Idaho,
Amaricnn Fisheries Sodety, Batha&, MD, USA.
Moscow, ID, USA.
M m c ~ ~W.
n , 1973. Fishes of Arizoua. Arizona Dcpubnant of Fiah and Game, Phwnix, AZ, USA. WEBB,P.W. 197.5. Hydrodynamics and enargatica
of freh propulsion. Fieherim Rcsamh Board of
PIMR., AND R. V. BULKLEY.1983. ConcanCanada Bullatin 190.
trations of total dissolved solids p r a f e d or
P, D., AND J. H. B R O U C I ~ O1965.
N . Annual
avoided by endangered Colorndo River WE. ZIMMER,
fish pmage report-Rock Islancl Dam Columbia
Transaction8 of the American Fieherb Society
River, Waahkqton, 1964, U.S. Fish and Wildlife
112:59S600.
&CHARD&
F. P., W. W. ~
o AND R ~W.
, Strdcc, Spacial Scientific Report Fishtrim 5 15.
-