BIOCHEMICAL GENETIC MARKERS FOR BROODSTOCK IDENTIFICATION IN AQUACULTURE1

Abstract

ABSTRACTGenetic variation in the structure of proteins and enzymes has within the past decade been recognized as a fundamental characteristic of life. The relative ease with which such biochemical variation may be detected in most organisms, together with its actual description in several molluscs, crustaceans and fishes having aquacultural potential, suggest that gene‐enzyme variation can be of significance in the development of aquaculture broodstock. Specifically, by serving to mark or identify individuals, populations, stocks or species, biochemical variants may become important tools in husbandry and breeding.Biochemical phenotypes revealed by electrophoresis and specific enzyme assay can serve as markers because of their detectability in milligram biopsy samples, their stability over a broad range of onto‐genetic and physiological states, and, in diploids at least, their single‐locus Mendelian inheritance with codominant expression. Previous studies on the lobster (Homarus americanus) illustrate the utility of molecular methodology in characterizing stocks obtained from nature, in confirming parentage in crosses, and in tagging progenies to be used in grow‐out experiments or in hatchery release programs. Moreover, rates of inbreeding among broodstock may be directly quantified by monitoring increases in homozygosity relative to natural populations. Biochemical genetic markers may thus be used to solve a number of diverse problems encountered in broodstock development.