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

I. Wild broodstock If it is determined necessary to conduct a propagation
program for a listed or candidate species, them the next step will be to determine
the type of broodstock program needed. The use of wild brood sources should be
considered first. Wild broodstocks have a number of advantages over other
techniques including; naturally maturing fish, adults remain in the wild, egg
quality, and reduced stress on the spawning fish. Adult wild broodfish should
always be our first choose as an egg source.
2. Captive Broodstock If captive broodstocks are determined to be necessary for
proper broodstock development during the founding phase is fundamental. The first
priority for obtaining founders for a broodstock is to select fish from
appropriate wild stocks or populations and use acceptable breeding strategies that
will maintain genetic diversity similar to the wild stock (Kapuscinski et al.
1993). If the stock has been extirpated or is extremely low, then founders should
be obtained that would be the nearest neighbor from an evolutionary (not
necessarily geographic) standpoint. Fish from nearest neighbor stock should
exhibit life history patterns similar to the extirpated population and be taken
from a similar environment.
It is especially important to obtain a random sample of fish that represent the
donor population by sampling adults throughout the spawning season. Unless the
species is in immediate danger of extinction, the number of wild fish removed at
any one time should be limited so the remaining population is not adversely
affected.
The importance of maintaining detailed and accurate records cannot be
overemphasized. Records should include the origin, genetic profile, and unique
identifying number of each adult broodfish, as well as its production record and •
progeny performance. Genetic characteristics of broodstocks and progeny must be
known so that reintroduction efforts can be monitored and evaluated to determine
survival of hatchery-reared fish and their interaction with wild stocks (Gauldie
1991; Hynes et al. 1981).
F. Estimating the Number of Fish Required to Develop Broodstocks. The number of
broodfish needed at the end of each growing season is dependent upon the attrition
rate, number of eggs per female, survival rate of eggs, and number of fish to be
stocked. If more fish are produced than are needed for broodstock development,
dispose of surplus fish according to guidelines provided in Section VI of this
document.
G. Important Broodstock Considerations. The following must be considered when
establishing broodstocks: (1) Equal sex ratios among breeding adults (Kapuscinski
et al. 1993; Lacava and Hughes 1989; Tave 1984); (2) equal numbers of offspring
among family lots from pedigreed matings (Allendorf 1993; Kapuscinski et al.
1993); and (3) avoidance of selection (Frankham et al. 1992; Kapuscinski et al.
1993). Failure to conside these factors can result in rapid loss of genetic
diversity in broodstocks (Allendorf 1993; Kapuscinski et al. 1993). Equal numbers
of fish from pedigreed family lots at the time of release will provide genetic
diversity that will maximize effective population size and reduce the potential
for inbreeding while enhancing the potential for adaptation and survival after
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