Mitochondrial variability of dolphinfish Coryphaena hippurus populations in the Pacific Ocean

Patterns of genetic structure among marine populations involve a variety of dispersal mechanisms and spatial scales. Pelagic species, such as the dolphinfish Coryphaena hippurus, epitomize the open and continuous nature of the marine environment due to their extensive migrations. Many studies have revealed that oceanic pelagic species tend to be genetically homogeneous over local and often extended geographic scales and only show levels of differentiation among estreme localities or ocean basins. Here were presented genetic data suggesting genetic heterogeneity in the dolphinfish at geographic scales much smaller than those predicted by that generalization. Mitochondrial NADH1 gene RFLPs revealed a highly significant Phi sub(ST = 0.029, P = 0.004, AMOVA) molecular genetic structure among fish from Baja California Sur (BCS), Sinaloa and Hawaii, consistent with heterogeneous haplotype frequencies (p = 0.014, exact test of genetic differentiation) and a depressed molecular diversity in fish sampled off BCS.)