Translocations and the preservation of allelic
Stockwell, C. A. M. Mulvey and G. L. Vinyard
Translocation is a tool commonly used for the conservation of threatened and
endangered fish species. Despite extensive use, the biological implications of
translocation remain poorly understood. Of particular interest is the effect of
translocation on genetic variability. Maintenance of genetic variability in refuge
populations is assumed to be important for both short- and long-term success. We
examined allozyme variability at 16 loci for mosquitofish (Gambusia affinis)
populations with known histories of introduction. Refuge populations had
significantly lower levels of heterozygosity. Refuge populations also had
considerably lower levels of allelic diversity than parental populations. All losses
were of relatively rare alleles (frequency less than 0.1 in parental population).
These losses were probably due to an undocumented bottleneck early in the
introduction history. These results were surprising because the initial transplant
involved 900 fish and because mosquitofish have numerous reproductive traits that
should minimize the effects of bottlenecks on genetic diversity. A literature review
revealed that genetic variability is often reduced in refuge populations, and that
such reductions typically involve the loss of alleles. We suggest that tranlocated
populations be examined periodically for losses of genetic variability.
SREL Reprint #2105
Stockwell, C.A., M. Mulvey, and G.L. Vinyard. 1996. Translocations and the
preservation of allelic diversity. Conservation Biology 10:1133-1141.
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