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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Specific Recommendation 2. Finalize and adopt the "Genetic Manage-
ment Plan" that is based on the information in Section V of this
document. The Service Endangered Fish Propagation Coordinator has
developed various draft guidelines for propagation of the endangered
Colorado River fishes (U.S. Fish and Wildlife Service 1992b, 1992c,
1993b; Williamson 1990, 1992a, 1992b, 1993a, 1993c). The
information in these various drafts should be summarized into a
"Endangered Fish Propagation Handbook" so that the information is
readily available as guidelines, policies, or references. The
information should be place in 3-ring binders with chapters
separated by index tabs so that revisions based on new information
can be inserted into the handbook. The U.S. Fish and Wildlife
Service "Inland Salmonid broodstock Management Handbook" can be
used as a model (U.S. Fish and Wildlife Service 1992a).
D. Important Considerations in Captive Propagation of Endangered Fishes.
Equal sex ratios among breeding adults (Kapuscinski et al. 1993; Lacava
and Hughes 1989; Tave 1984), equal numbers of offspring among family lots
from pedigreed matings (Allendorf 1993; Kapuscinski et al. 1993),
extended intervals between generations, and avoidance of selection are
important in maintaining large effective population sizes and genetic
diversity of broodstocks in captive breeding programs (Frankham et al.
1992; Kapuscinski et al. 1993). Ignoring these factors has resulted in
rapid loss of genetic diversity in broodstocks under captive rearing
conditions (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 increase effective population size and reduce
the potential for inbreeding while enhancing the potential for adaptation
and survival after stocking (Allendorf 1993; Kapuscinski et al. 1993).
Captive rearing of endangered fish results in a gain in total offspring
but with a tradeoff in which there may be a simultaneous reduction in the
effective population size (Ryman and Laikre 1991). A reduction in
effective population size will be accompanied by excessive loss of
genetic heterozygosity. This is especially true if the absolute size of
the wild population is small. Ryman and Laikre (1991) strongly recommend
that the risk of losing genetic variability through captive breeding
should be carefully considered even if only a single stocking is to be
made. Precautions that will be taken during propagation and stocking are
summarized by priority in Box 8. Genetic characteristics of broodstocks
and progeny must be known so that augmentation or reintroduction efforts
can The monitored and evaluated to determine survival of hatchery-reared
fish and their interaction with wild stocks (Gauldie 1981; Hynes et al.
1981).
I E.

effective population size (K e)
genetic diversity because the
heterozygosity is proportional
size (Ryman and Laikre 1991).
is
rate
to
a key parameter
of inbreeding
the inverse of
of Endangered Fish. The
in conservation of
and the loss of genetic
the effective population
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