A genetic marker for artificially reared cod (Gadus morhua L.)

Abstract

Artificially reared cod at the Aquaculture Station Austevoll on the west coast of Norway, were screened for genetic markers by using biopsies of white muscle, individual tags and enzyme genotype as determined by starch gel electrophoresis. In February 1986, 70 parental fish, all heterozygote for a rare allele in phosphoglucose isomerase (PGI-1(30)), were selected and placed in a spawning tank. The fish spawned naturally, and in all samples of offspring the PGI-1(30/30) homozygote accounts for about 25% of total offspring. At present 3 500 cod are kept in net pens, where 847 individuals are positively identified as PGI-1 (30/30) homozygotes and raised as broodstock. Offspring from this genetically tagged cod will be used in farming and/or stock enhancement programmes in the future.