7315

• UCREFRP Catalog Number: 7315
• Author: Colorado Water Conservation Board.
• Title: State of Colorado Hatchery Feasibility Study for Endangered Fishes of the Colorado River Basin, Vols. 1 & 2.
• USFW Year: 1993.
• USFW - Doc Type: \
• Copyright Material: NO

~CE NUMBER:
CITATION:

023

Toney, D.P. 1974. Observations on the propagation and rearing of
twO endangered fish species in a hatchery environmenL Proceedings
of the Annual Conference of the Western Association of State FISh
and Game Commissioners 54:252-239.

SPECIES AND LIFE STAGE:

cs, CS_EGG, CS_ADULT. RZ, RZ_EGG, RZ_LARV AE,
RZ_JUV, RZ_ADULT

TOPICS:

Disease, Production, Culture Techniques, Temperature, Diet

KEYWORDS:

COLORADO SQUA WFISH, RAZORBACK SUCKER,
BROODSTOCK, HOLDING FACn..rrIES, DIET, GROWTH,
DISEASE, SPAWNING, HATCHING

SUMMARY: Colorado squawfish and razorback suckers were reared at the Willow Beach National Fish
Hatchery. Eggs from the suckers were hand stripped from wild (Lake Mohave) stock.
Squawfish eggs were collected from natural spawning in a hatchery raceway.

.

Seven squawfish from the Yampa River were placed in a concrete raceway (100' X 8' X 30.).
Gravel was placed in the first 30' of the holding raceway and water was pumped into the
raceway at 200 galJmiD. The squawfish were fed live trout three to four times daily. Combined
weight of the fish increased from 227 pounds in August 21, 1973 to 24.1 pounds on May 30,
1974. Ninety pounds of trout were fed the squawfish over this nine month period for a total
oollVClSion of 1.4 pounds. The only disease organisms found were Mvxobolus. Lernaea and
Ichthvopbthirius. Formalin (25 mg/l) and malBchite green (.05 mg/l) were used for three weeks
as controL Three females were induced to spawn by injection of 900 units/lb of chronic
gonadotrOphin. Eggs were discovered in the gravel one week later.

Forty razorback suckers were collected from Lake Mohave. Eggs were hand stripped and
placed in hatchery tank (3' x 15'). Water in the tank was 2 feet deep and averaged 600F. After
hatching the fry were fed small amounts of baby food, strained beef liver, four or five times
daily. After three weeks the fry were moved outside and fed on zooplankton found in the
hatchery raceways. IchtvOohthirius were observed on the fry and treated with formalin and
mlllllcbite green. Mvxosoma spores were found on the adult razorbacks.

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