7306

• UCREFRP Catalog Number: 7306
• Author: Tyus, H. M. and C. W. McAda
• Title: Migration, Movements and Habitat Preferences of Colorado Squawfish,
• USFW Year: 1984
• Copyright Material: YES

292

The Southwestern Naturalist

Au!{ust 19H1

vol. 29, no. 3

'i
;TABI... I.-Capture, release and total movement of radiotelemetered Colorado squawfish

monitored three months or more /980-8/.

2
160
12
80
l/)
Ct:
W
~
w
:E 0
0
..J
~

1'01,,1
1.1'111-:'111 Dall' Dalt'of
Fish No Fish (nun) RiwI1 Rl'!t-as('d Dall' (;ollla( I~
I ',08 (; 1-21-HO 8-20-80
2 51\ G/W/n 1-21-80 9-02-HO RC
2 OJ I 0 G 5-13-HO 8-08-80 RC
1 525 G 5-13-80 8-20-80
5 421 G 4.13-81 7.15-81
6 171 G 4-13-81 9-10-81
7 611 G/Y 5-01-81 9-01-81
8 601 G 5-11-81 8-25-HI
9 533 Y 4-2.1-81 H-18-81
10 .120 y 4-25-HI H-05-81
II 624 y 5-12-81 9-03-81
12 512 y 5-12-81 8-27-81
13 601 y 5-11-81 9-09-81
14 450 W 4.15-81 8.31.81
IS 5.10 WIG 5-29-81 10-07-81
IG :;:: GTet'fl, W =::- White, Y = Y<.Impa, 0 = Duchesne
2RC:;: Rt'{'apIUTt'd
1m == mi~ralOry, s = sedenlary, I = coman losl lOT a month Of mort'

Majol
MllVnnt'Il1
(kill)

1\111\'('111('111
Palu'III-'

1.1.1
3.16
29

m
m

317 m
247 m
157 m
336 m
306 m
230 m
86
611 m

advanced stage of sexual maturity. The total lengths of the remaining two
sedentary fish were 421 and 450 mm respectively, and these were probably
immature also. These findings were consistent with the work of Seethaler
(1978), who indicated that Colorado squawfish of this size were probably
immature.
All seven fish implanted in the Yampa River exhibited high mobility and
this movement pattern (Fig. 2) was conclusively linked with spawning. In
late June, all Colorado squawfish implanted in the Yampa River began
moving downstream from their original points of capture and in early July
were relocated in the lower 32 km of Yampa Canyon. By late July (Fig. 2)
all the radio tagged fish had left the lower Yampa Canyon and when
relocated, were generally found at the same area of initial capture. While
these fish were located in Yampa Canyon a Colorado Squawfish (No. 525;
radiotagged in the Green River near Ouray, Utah was found in association
with them. This fish also returned to its initial location in late July
Altough objectives of the Yampa study did not permit disturbance 0
radio tagged squawfish, extensive collecting with floating trammel nets wa:
conducted near them, and one radiotagged fish was accidentally captured
The fish was a ripe male, heavily tuberculated and flowing milt
Collections made from 1 July to 9 July 1981 produced an additional 3:
Colorado squawfish in spawning condition. These fish were either rip
males or spent females and all were taken from short pool-riffle-poc
habitat sections in the lower 32 km of Yampa Canyon.
It was concluded that the movement into the lower Yampa Canyo
represented a major spawning migration and demonstrates homing abilit~
for which the mechanism is unknown. This migration is probably
repeated seasonal event since Holden and Stalnaker (1975) report~

Tyus and McAda-Squawlish Movements

80

12

160

2

MAY

JI,JNE

293

JULY

AUG

SEPT

FIG. 2.-Movement 01 8 radioLa!{!{ed Colorado squawlish. Yampa River 1981.

MONTH

increased numbers of ripe Colorado squawfish in the lower Yampa River
in July of 1968-70. Seethaler (1978) also found increased numbers of
Colorado squawfish in this area during the month of July in 1974-75.
Data from conventional tag recaptures (Table 2) substantiated the
movement exhibited by the radiotelemetered fish in the Yampa River. Four
Carlin dangler tagged Colorado squawfish were recaptured on the spawning
grounds. Two of these were tagged on the upper Yampa in August 1978
and 1980, one was tagged in the upper Green in May 1981 and one was
a local recapture.
The presence of ripe Colorado squawfish does not necessarily reflect a
spawning area, since ripe males can be stripped of milt for an extended