POPULATION GENETIC STRUCTURE OF THUNNUS OBESUS IN CENTRAL PACIFIC OCEAN
WU Zhi-Chao;XU Qiang-Hua;XU Liu-Xiong;DAI Xiao-Jie;ZHU Jiang-Feng;College of Marine Sciences,Shanghai Ocean University;Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resource Ministry of Education;Scientific Observing and Experimental Station of Oceanic Fishery Resource Ministry of Agriculture;National Distant-water Fisheries Engineering Research Center;
Overexploitation of bigeye tuna in the Central Pacific Ocean has become a serious concern. We investigated the population genetic structure aiming at providing scientific references for the sustainable development of the resources. In this study, 182 bigeye tuna specimens were sampled from the Central Pacific Ocean. Population genetic diversity was evaluated by using the sequence data of the first HVR-1(hypervariable region, HVR-1) of mitochondrial control region. In total, 115 variable sites were observed and 178 haplotypes were identified. Analysis of mtDNA HVR-1 sequences of bigeye tuna from eight localities with the nucleotide diversities ranged 0.03074-0.04362 and high haplotype diversities ranged 0.996-1.000. AMOVA test of bigeye tuna revealed that 99.97% of the genetic variation occurred within populations. Low Fst(fixation index) values and high gene flow(Nm) values revealed in this investigation indicate no significant genetic differentiation and high rates of gene flow between the Central Western Pacific bigeye tuna populations and the Central Eastern Pacific bigeye tuna populations.