Genetically structured population and demographic history of the goldlined spinefoot Siganus guttatus in the northwestern Pacific
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- Iwamoto, K., Chang, CW., Takemura, A. et al. Fish Sci (2012) 78: 249. doi:10.1007/s12562-011-0455-3
Sequence variation of the mitochondrial DNA was analyzed to examine the genetic structure and demographic history of the goldlined spinefoot Siganus guttatus in the northwestern Pacific. In total, 451 nucleotide sequences spanning from the tRNAThr gene to the middle of the control region were determined from 254 specimens collected from five localities; three in the Ryukyu Islands (Okinawa, Miyako, and Ishigaki Islands), Taiwan, and Cebu Island of the Philippines; 73 variable sites and 75 haplotypes were detected. Our results showed restricted gene flow and genetic differentiation among all populations, with the exception of genetic homogeneity between the Miyako and Ishigaki populations; that is, this species will be able to cross between Miyako and Ishigaki (ca. 120 km) by the transport of pelagic larvae, and gene flow between Okinawa and Miyako/Ishigaki Islands (ca. 330–450 km) is restricted. A non-dispersal strategy will lead to restricted gene flow and genetic structuring in S. guttatus. Both the neutrality tests and the mismatch distribution indicated that S. guttatus might have been in populations at demographic equilibrium. This suggests that population range expansion may have been restricted owing to a non-dispersal strategy that may have restrained S. guttatus from demographic expansion after glaciation. The result will be of fundamental importance for resource management of this species.