Loss of genetic variation in hatchery-produced abalone, Haliotis iris.
Genetic differences between samples of abalone seed produced in a hatchery and those of wild abalone were studied by gel electrophoresis. There was a significant change between wild and hatchery samples in allele frequency, a loss of rare alleles, and a reduction in heterozygosity at a phosphoglucomutase locus. At a superoxide dismutase locus there was a loss of genetic variation, samples of hatchery seed being fixed for the common wild allele. It is recommended that abalone hatcheries use a minimum of 5 ♂♂ and 5 ♀♀ to reduce the risk of losing genetic variation in the hatchery seed; in practice this requires 10-13 ♂♂ and 25-30 ♀♀ in the spawning tanks.