Heterogeneity in Philippine milkfish populations

Twelve milkfish (Chanos chanos ) populations from 6 coastal areas in the Philippines, collected at the fry stage and reared until fingerling size, were analysed for electrophoretic variation at 28 presumptive loci. Seven loci were polymorphic at the 0.99 level (5 at the 0.95 level) while 21 were monomorphic. Significant departures from the expected Hardy-Weinberg genotype distributions were observed only at the Pgm locus in samples 843 and 862. G-tests for heterogeneity revealed significant differences in genotype distributions at the Est-1, Gpi-1, Gpi-2, Mp-2 and Pgm loci within each year of sampling, within one location at different sampling years, and within two geographical areas east and west of the Philippines