抄録
Allelic isozymes were examined in Platichthys stellatus and Kareius bicoloratus collected in Sendai Bay. Of the 32 genetic loci examined, the 9 loci were divergent and the other loci were non-divergent and polymorphic. With one exception, all of these divergent loci were polymorphic in P. stellatus but the commonest alleles were different from these homozygous in K. bicoloratus. The secondary alleles of these loci were identical to those homozygous in K. bicoloratus.
A comparison was made between biochemical and morphological characters to detect natural hybrides in fish populations. The dextral fishes of P. stellatus showed hybrid patterns in all of the 9 divergent loci, indicating that they were F1 hybrids between P. stellatus and K. bicoloratus. From the distribution and frequencies of the secondary alleles in P. stellatus population, an amount of introgression between both species can be estimated.
