9428

• UCREFRP Catalog Number: 9428
• Author: Erdahl, D. A.
• Title: Inland Salmonid Broodstock Management Handbook.
• USFW Year: no dat
• USFW - Doc Type: Bozeman.
• Copyright Material: NO

4. Unintentional Selection
Selection may occur without the culturist even being-aware it
is happening. It-can also occur in spite of the best efforts
to prevent it. For example, the genetic variability of a
population of wild fish removed from the wild and reared at a
hatchery has only one direction it can go.....downward.
Loss of variation in this situation- can be slowed, but not
eliminated.
In review, the loss of genetic variation is caused by:
1. Genetic Drift (random loss)
2. Inbreeding (mating of related individuals)
3. Intentional Selection
4. Unintentional Selection (domestication)
It is obvious ,that loss of variation in cultured fish stocks is an
undesirable situation. Measures to reduce this loss of variation
will ..likely result: in modifications of many current management
.practices. Although new management practices may result in some
immediate discernable beneficial .effects, the true benefits of
maintaining or increasing genetic variation will become more
apparent. in the future....
Methods to Minimize the Loss of Genetic Variation
1. Collect Baseline Data
In order to determine the genetic health of a broodstock
population, it is necessary to collect baseline genetic
information. Data that should be collected includes:.
A. An electrophoretic analysis of each species and
strain
B. Asymmetry counts of each species and strain
C. Any other methodologies that gain acceptance
(e.g. DNA analysis)
~ Basic. genetic information on specific species or strains can
be obtained by contacting Dr. Robb Leary or Dr. Fred
Allendorf, Division of Biological Science, University of
Montana, Missoula, MT 59812 (ph. 406-243-5503). The cost
for electrophoretic analysis and asymmetry counts on most
species of trout is $1000 (50 fish sample). The, charge for
cutthroat trout is $1500.
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