Population Genetic Analysis of Striped Dwarf Catfish Golsha, Mystus cavasius (Hamilton 1822) Using Allozyme Markers in Bangladesh

Population genetic variation, in four populations of golsha, Mystus cavasius (Hamilton 1822) from Bangladesh, namely the Bulla River, the Dhonu River, the Mithamoin haor (dead basin of oxbow lakes) and the Bonhi baor (closed waterlogged areas), were analysed using allozyme markers. Seven loci encoded in muscle and liver tissues by four enzymes were examined using starch gelelectrophoresis. Five loci were polymorphic (P99). The mean proportion of polymorphic loci was highest (71.43%) in the Mithamoin haor population whereas the highest mean number of alleles per locus (2.143) was observed in both the Mithamoin and Bonhi baor populations. The observed and the expected heterozygosity (0.176 and 0.193 respectively) were highest in the Bonhi baorpopulation. None of the pairwise FST values was statistically significant. The highest (0.109-0.125)FST and genetic distance (D) values were found between the Bonhi baor and all other populationsreflecting the more distant location, in a separate catchment, of the Bonhi population. The geneticdistance also showed the Bonhi as an outlier separated from other three populations. Although theDhonu and to a lesser degree, the Bonhi populations showed some evidence of deviation fromHardy-Weinberg equilibrium, all populations had sufficient variation for use in selective breedingprogrammes and for the commercial propagation of golsha as future broodstocks.