Population genetic structure of the pelagic goby, Sufflogobius bibarbatus, in the Northern Benguela ecosystem, based on PCR-RFLP analysis of the mitochondrial control region and the ND 3 and 4 region (Dissertation).

AbstractPolymorphism within the mitochondrial NADH-3,4 dehydrogenase(ND-3/4) and control region (D-Loop) was studied by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of Sufflogobius bibarbatus (Pelagic Goby) population in the Northern Benguela ecosystem. Three major geographical areas representing the north-south axis (Ludritz, Walvis Bay and North of Ambrose Bay) were selected. Polymorphism was detected using three and two restriction enzymes respectively in ND- 3 / 4 and D-Loop regions, and a total number of 25 composite haplotypes were identified. The most common haplotype accounted for 36% of 238 individuals. Recorded haplotype diversities were quite high, ranging 0.70 to 0.86.The highest haplotype diversity was found in Walvis Bay followed by Ludritz and North of Ambrose Bay. Pairwise Fst values among regions indicated that significantly population differentiation existing. The Monte Carlo test revealed a significant difference among three geographical areas (P <0.05). Pairwise comparisons based on haplotype frequencies revealed significant differences between Ludritz and Walvis Bay (P < 0.05) and Ludritz and North of Ambrose Bay (P < 0.01) while no difference was found between Walvis Bay and North of Ambrose Bay (P >0.05).Similar observations were found by Exact test for haplotype frequencies. This study has shown existence of population subdivision of the pelagic goby in the Northern Benguela. Combination of factors like complex circulation pattern, physical barrier around Moeb Bay and adaptive selection can be contributed to the observed divergence. Identified population sub structure will be vital in future decision and policy making of the proposed ecosystem based management in the Benguela region.