GENETIC COMPARISON BETWEEN PACIFIC HERRING (CLUPEA-PALLASI) AND A NORWEGIAN FJORD STOCK OF ATLANTIC HERRING (CLUPEA-HARENGUS)

Genetic studies on populations of Atlantic herring (Clupea harengus L. ) in Norwegian seawaters have revealed a number of genetically distinc t fjord populations. One population in Balsfjord in northern Norway wa s nearly fixed for several alleles that were very rare in the Atlanto- Scandian herring stock. A comparison with a sample of Pacific herring (Clupea pallasi) from British Columbia demonstrated that these alleles were identical to the more common alleles in this species. Genetic di stance estimates based on six polymorphic loci demonstrated that Balsf jord herring were more similar to Pacific herring. Balsfjord and Pacif ic herring were also similar in vertebrae number and spawning behaviou r. Restriction fragment analyses of mitochondrial DNA using five restr iction enzymes revealed distinct clones that separated different herri ng groups. Nucleotide sequence divergence among groups was small.