Recent population expansion of longtail tunaThunnus tonggol(Bleeker, 1851) inferred from the mitochondrial DNA markers

• DOI: 10.7717/peerj.9679
• Publication Date: 2020-08-06T08:10:47Z
• Authors: Noorhani Syahida ...; Tun Nurul Aimi Ma...; Rumeaida Mat Piah; Wahidah Mohd Arshaad; Siti Azizah Mohd Nor; Ahasan Habib; Mazlan Abd. Ghaffar; Yeong Yik Sung; Muhd Danish-Daniel; Min Pau Tan
• Keywords: Panmixia; Nucleotide diversity; Thunnus

The population genetic diversity and demographic history of the longtail tuna Thunnus tonggol in Malaysian waters was investigated using mitochondrial DNA D-loop NADH dehydrogenase subunit 5 (ND5). A total 203 (D-loop) 208 (ND5) individuals T. were sampled from 11 localities around coastal waters. Low differentiation between populations found, possibly due to past history, dispersal potential during egg larval stages, seasonal migration adults, lack geographical barriers. gene trees, constructed based on maximum likelihood method, revealed a single panmictic with unsupported internal clades, indicating an absence structure among studied. Analysis pairwise comparison ФST suggested limited flow study sites. Taken all together, high haplotype (D-loop = 0.989-1.000; ND5 0.848-0.965), coupled low level nucleotide 0.019-0.025; 0.0017-0.003), "star-like" network, unimodal mismatch distribution, suggests recent expansion for Malaysia. Furthermore, neutrality goodness fit tests supported signature relatively Pleistocene epoch. To provide additional insight into phylogeographic pattern species within Indo-Pacific Ocean, we included haplotypes GenBank few samples Taiwan. Preliminary analyses suggest more complex demarcation than explicit Indian Ocean versus Pacific delineation.