The genetic population structure of red snapper Lutjanus malabaricus and orange-spotted grouper Epinepheluscoiodes in Brunei and Sabah was investigated using allozyme electrophoresis. Samples were collected from three...The genetic population structure of red snapper Lutjanus malabaricus and orange-spotted grouper Epinepheluscoiodes in Brunei and Sabah was investigated using allozyme electrophoresis. Samples were collected from threesites in Brunei for E. coiodes and from three sites in Brunei and Sabah for L. malabaricus. A total of 22 loci and 16loci were scored, respectively. The index of fixation (FST) for the E. coiodes population was 0.176 but, in general, itlacked within-population structuring. The FST was particularly high between Brunei Bay/Jerudong and Brunei Bay/Kuala Belait, suggesting genetic subdivision on a small spatial scale. Isolation of Brunei Bay from the South ChinaSea may constrain the movement of adult fishes and larval dispersal, thereby reducing homogeneity amongsubpopulations. All variable loci for E. coiodes were in Hardy–Weinberg equilibrium except for MDH* and GTDHP*(P < 0.01), in which two subpopulations showed an excess of heterozygotes (P < 0.01). The study on the L.malabaricus population showed a heterozygote deficit of approximately 60% in variable loci (FIS, genetic variationwithin population = 0.45;P < 0.05);however, the mean observed heterozygosity for the population far exceeded L.malabaricus populations in Australia and Indonesia. A FST value of 0.076 revealed moderate genetic differentiationamong subpopulations of L. malabaricus. The genotypes were likely to be drawn from the same distribution inJerudong and Kuala Belait. This study infers that sustainable management of snapper and grouper resources inBrunei waters must take into account the presence of a single stock and two stocks, respectively.展开更多
基金the Universiti Brunei Darussalam through research grant no.PNC2/2/RG/1(18).
文摘The genetic population structure of red snapper Lutjanus malabaricus and orange-spotted grouper Epinepheluscoiodes in Brunei and Sabah was investigated using allozyme electrophoresis. Samples were collected from threesites in Brunei for E. coiodes and from three sites in Brunei and Sabah for L. malabaricus. A total of 22 loci and 16loci were scored, respectively. The index of fixation (FST) for the E. coiodes population was 0.176 but, in general, itlacked within-population structuring. The FST was particularly high between Brunei Bay/Jerudong and Brunei Bay/Kuala Belait, suggesting genetic subdivision on a small spatial scale. Isolation of Brunei Bay from the South ChinaSea may constrain the movement of adult fishes and larval dispersal, thereby reducing homogeneity amongsubpopulations. All variable loci for E. coiodes were in Hardy–Weinberg equilibrium except for MDH* and GTDHP*(P < 0.01), in which two subpopulations showed an excess of heterozygotes (P < 0.01). The study on the L.malabaricus population showed a heterozygote deficit of approximately 60% in variable loci (FIS, genetic variationwithin population = 0.45;P < 0.05);however, the mean observed heterozygosity for the population far exceeded L.malabaricus populations in Australia and Indonesia. A FST value of 0.076 revealed moderate genetic differentiationamong subpopulations of L. malabaricus. The genotypes were likely to be drawn from the same distribution inJerudong and Kuala Belait. This study infers that sustainable management of snapper and grouper resources inBrunei waters must take into account the presence of a single stock and two stocks, respectively.
