Genetic characteristics and relationships of climbing perch Anabas testudineus populations in Thailand

Seven natural populations of climbing perch Anabas testudineus collected from the central, eastern, and peninsular areas in Thailand were assayed by allozymic analysis to examine genetic relationships among geographic populations. Twelve out of 18 enzyme loci were polymorphic. Significant differences in allelic frequencies were observed in all pairs of populations at one or more loci, and six loci showed the regional characteristic allelic compositions. Genetic distance between populations was higher between areas, in comparison with those within an area, being significant between the peninsular and the other populations. According to a UPGMA tree based on a genetic distance matrix, the seven populations fell into three major clusters in line with the area divisions. These groupings indicate that genetic relationships among climbing perch populations are much the same as for other freshwater fishes, and would depend on geographic features such as the river systems in Thailand.