Low Genetic Differentiation with High Genetic Variability Observed in Common Coastal Starfish Asterina pectinifera around Japan Inferred from Isozyme Analysis

Abstract

Genetic variability and geographic population structure in population of the common coastal starfish Asterina pectinifera were examined in nine localities around Japan through isozyme analysis. Surveying 28 enzymes by using starch gel electrophoresis, it was found that eight loci controlling seven enzymes were useable as genetic markers. Genetic variability of this species estimated from the 8 loci followed ; the proportion of variant loci ranged from 0.63 to 1.00 with a mean of 0.80, expected average heterozygosity was from 0.176 to 0.208 with a mean of 0.184, and mean number of alleles per locus ranged from 2.5 to 3.8 with a mean of 3.0. The genetic variability of this species was comparatively high among aquatic animals. In order to evaluate genetic differences among the nine localities around Japan, the allelic and genotypic homogeneity tests were carried out and Nei\u27s genetic distance was calculated between every pair of the nine localities. Significant differences among localities showed at only a few loci, but genetic distances were low between any pair of localities. Thus, genetic differentiation has not occurred among localities around Japan in A. pectinifera