Genetic variability in marine bivalvia: implications and applications in molluscan mariculture

Permission to include this article in this repository has been obtained from the author, Professor Noël P. Wilkins.The extent of genetic variability at enzyme gene loci is assessed in twelve species of marine bivalve molluscs of actual or potential commercial importance. Approximately one third of these loci are polymorphic, average heterozygosity is 0.14, and an average of 3.9 alleles are segregating per polymorphic locus. Hatchery-produced samples exhibit a lower proportion of polymorphic loci and a loss of some alleles at polymorphic loci. In two hatchery-produced families of Crassostrea gigas, phenotype frequencies at two loci depart from Mendelian expectations in young individuals. The implications of these hatchery induced alterations are discussed, together with some possible applications of biochemical genetics in molluscan mariculture