7890

• UCREFRP Catalog Number: 7890
• Author: U.S. Fish and Wildlife Service.
• Title: Region 6, Fish and Wildlife Service Guidelines Directing Captive Propagation Of Listed And Candidate Fish.
• USFW Year: 1996.
• USFW - Doc Type: \
• Copyright Material: NO

If space is limited for propagation of all family lots resulting from a 5 X 5 di-
allele cross, maintaining separate groups of the 5 unique family lots represented
in the diagonal cells would be preferred to maintaining the 20 other matings.
These 5 family lots contain the entire genetic contribution from the 10 parents.
After a broodstock has been developed from a 5 X 5 cross or a factorial mating,
additional wild fish should be used to supplement the genetic contribution of the
parent stock until a minimum effective population size of 50 is achieved..
Additional lots from mating one male with one female should replace half-sib lots
in the di-allele cross to maximize the genetic contribution from wild parents.
In many situations, it will be feasible to spawn wild fish at the site of capture
and return them to their original habitat immediately. This should always be our
first option. There are many advantages including: less stress on the mature
adult fish, ability to quickly return the fish to its natural habitat, keeps the
adult fish in the wild, potentially less mortality to spawning fish, and others.
This strategy has been used on arctic fluvial grayling, greenback cutthroat trout
and will be attempted on pallid sturgeon in 1995. The practice has been highly
successful and a great deal more emphasis must be placed on this technique in
obtaining eggs.
However, in some situations, it may be necessary to collect, transport and hold
fish until they can be spawned. The stress of capture and transporting may
prevent broodfish from spawning during the year of capture. Even if fish spawn in
the year of capture or a subsequent year, wild adults may be retained at the
refuge or hatchery for an additional year to ensure that F, progeny survive from
the initial spawning,before returning adults to the wild.
x VI. GUIDELINES FOR DISPOSITION OF CAPTIVE-REARED LISTED AND CANDIDATE FISH
A. Background. Propagation activities may produce more fish than are needed to meet
specified requirements. This additional production allows the hatchery manager to
compensate for unknown or unpredictable attrition rates and ensure that specified
requirements are met. These guidelines provide the protocol for disposition of
such fish.
Planned captive propagation minimizes the production of listed or candidate fish
that will be excess to program needs. The number of fish that are reared depends
upon:
1. Captive propagation goals and objectives
2. Breeding strategy or mating system used
3. Fecundity of the fish
4. Anticipated mortality during culture
5. Method used to culture fish
6. Uncertainty of production during captive culture
7. Availability of culture facilities
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