8123

• UCREFRP Catalog Number: 8123
• Author: Wydoski, R. S.
• Title: Coordinated Hatchery Facility Plan
• USFW Year: 1994.
• USFW - Doc Type: Need for Captive-Reared Endangered Fish and Propagation Facilities.
• Copyright Material: NO

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To determine the number of 7-inch razorbacks represented by the 1,960
pounds, simple refer to the length-weight tables in Piper et al.
(1982) using a condition factor of 4.5 x 10-'. Razorbacks that are 7

inches in length will be approximately 6.3 fish per pound. If 6.3 '
fish per pound is multiplied by the weight of 1,960 pounds, the result
is 12,348 fish (6.3 fish per lb X 1,960 lbs = 12,348 fish). The

volume of water needed for these fish can be calculated by dividing 7 ,
inches by 2 one-half the length to obtain the weight of fish per cubic
foot of water (7 inches divided by 2 = 3.5 lb per ft'). By dividing
the total weight of fish (1,960 pounds) by the weight of fish that
require 1 ft' of water, the result is 560 ft' (1,960 pounds divided by
3.5 lb per ft' = 560 ft').
Typical raceway-type facilities for the 7-inch razorback suckers t
described above, chubs, and squawfish would be 4' wide X 50' long X 2'
deep with an average water depth of 18 inches and an inflow of 95 gpm
in each raceway. Total cubic feet of water (i.e., space) available
for the fish would be 600 cubic feet.
4. Reduce Water Reouirements with Water Reuse Systems. Water reuse '
systems can be used to reduce water requirements and to reduce costs
of heating water. The principal components of water reuse systems
include ammonia removal, disease control, temperature control,

aeration, and particulate filtration (Lucchetti and Gray 1988). '
Because unionized ammonia is produced as a metabolic waste and is
highly toxic to fish, a principal function of water reuse systems is
the biological removal of ammonia chiefly with Nitrosomonas and '
Nitrobacter bacteria. There is a risk that water reuse systems will
malfunction resulting in complete mortality of the fish. Therefore,
such systems must be used with extreme caution. However, if the

available water is limited and energy costs to heat water are high, '
water reuse systems can be used to compensate for these factors.
Consultation with hatchery managers and bioengineers who use water
reuse systems would be highly desirable to understand the advantages ,
and limitations of such systems and safety precautions that can be
taken to avoid mortality of fish if the system should fail. Typical
water reuse systems require about 10% makeup water per day. '
5. Combination of Indoor and Outdoor Culture of Endangered Fishes During
the First Growing Season. A combination of intensive-extensive or

indoor-outdoor fish culture methods provides another option for '
genetics management and production in propagation of endangered
fishes. For example, a unique family lot is produced by controlled
spawning of one male and one female. The mature fish are marked to '
identify fish from the paired mating. The fertilized eggs are
incubated by family lot in indoor facilities (i.e., in a hatching jar)
and the F, progeny are reared separately until they can be marked for
future identification. Larval fishes may be reared intensively
indoors on Artemia (brine shrimp), naturally-produced zooplankton,
artificial food, or combinations of the these food items. If water

quality, rearing volume, food, or labor become limiting, the young '
fish can be moved outdoors to small, fertilized ponds (e.g., one
family lot per 0.1-acre pond). If none of the above factors become
limiting, culturing the fish in outdoor ponds may still be preferred ,
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