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

. REFERENCE NUMBER:
CITATION:

012

I-Iamm"n, R.L. 1987. Survival of razorback suckers cultured in
earthen ponds. Progressive Fish-CulturisL 49(2):138-140.

SPECIES AND LIFE STAGE:

RZ, RZ_LAR

TOPICS:

Production. Culture Techniq~ Diet, Temperature

KEYWORDS:

RAZORBACK SUCKER, FEEDS, EARTHEN PONDS,
FERTTT J~ STOCKING RATE, FOOD CONVERSION RATE,
SWIM-UP FRY, TOTAL LENGTIi

SUMMARY:

Razorback sucker swim-up fly, sub-fingerlings, and fingerlings were successfully reared in
earthen ponds at Dexter National FISh Hatchery in 1985. Swim-up fly were stocked in 0.34 _
1.08 acre ponds at densities of 101,000 - 109,000 fly/acre. Fry averaged 71,000 per lb. Seven
~ prior to stocking fly, ponds were treated with alfalfa pellets at 300 lb/acre and
superphosphate at SO lb/acre. After initial treatment two ponds received 5 weekly fenilizations
of alfalfa pellets at 100 lb/acre and the two larger ponds received 3 weekly fertilizations of
alfalfa pellets at 100 lb/acre and superphosphate at 25 lb/acre. Fry were reared 69 - 78 d in
9 - 22"C water. Survival ranged from 87.8 - 98.6%, and size varied from 724 to 508 per pound.

.

Sub-fingerlings were stocked in ponds 3-4 ft deep and 0.86 - 0.98 acre at densities of 51,000-
58,OOOIaae. FISh ranged from 724 to 549 per pound. Prior to stocking, ponds were given a
single treatment of alfalfa pellets at 100 lb/acre. FISh were fed number 1 and 2 granules of
commercial trout diet at a rate of 5.5%l1b body weighL Survival of fish reared 51 - 70 d at
temperatures of 16 - 22"C ranged from 92.7 - 95.8%. Size of sub-fingerlings varied from 141 _
159 per pound. The pond with a single treatment of alfalfa pellets had the highest survival
rate but also the highest food conversion (267) of the test ponds.

Fmgerlings were stocked in ponds 0.98 acre and 3 ft in depth at densities of 26,000 _
27,000/acre. FISh averaged 158 per pound and were fed number 2 and 3 granules of
commercial trout dies at a rate of 5.0 - 3.5% per pound of body weight. Survival of fish reared
50 - 55 d at temperatures of 19 - 240C was 96.2%. Size of fish varied from 61.5 to 75.0 per
pound. Food conversion averaged 238.

Razorback sucker culture techniques have consistently improved since the transfer of the
program to Dexter National FISh Hatchery in 1981. Survival has gone from 10.8% in 1981 to
91.8% overall in 1985. This improvement has been contributed to management practices such
as fertilization rate and stocking rate refinement of pond culture.

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