Biochemical evidence of speciation in the cod genus Gadus

Isozyme data obtained from 13 enzyme systems encoded by 21 presumptive gene loci were used to investigate members of the cod genus Gadus; 10 loci were polymorphic. On the basis of our data we do not reject the view of conspecificity between the Baltic cod, G. morhua callarias, and the Atlantic cod, G. m. morhua, or between the ogac, G. m. ogac, and the Pacific cod, G. m. macrocephalus; the data do indicate that these two groups are specifically distinct.