GENETIC-VARIATION AT ISOZYME LOCI IN BLUE WHITING FROM THE NORTHEAST ATLANTIC

Genetic variation in blue whiting Micromesistius poutnssou was investi gated by starch gel electrophoresis of enzymes in tissue extracts. A t otal of 130 specimens from the spawning areas west of the British Isle s were collected from trawl catches in 1990 (n=30) and 1992 (n=100). I n 25 tissue enzyme loci screened for genetic variants in the 1990 samp le, polymorphisms (0.95 criterion) were found at IDDH-2, IDHP-2* and PGM-1, giving a frequency of polymorphic loci of P-0.95=0.12. In pool ed samples the average heterozygosity per locus was estimated at (H) o ver bar(e)=0.043 and the effective number of alleles per locus at 220, 1.45 and 1.53, respectively, for IDDH-2, IDHP-2* and PGM-1*.