High sequence variation and low population differentiation of mitochondrial control regions of wild Large yellow croaker in South China Sea

As a highly successful mariculture candidate endemic to China, the wild genetic resource of Large yellow croaker (Larimichthys crocea) have collapsed in the northern and central East China Seas, which has impeded the wild sampling and assessment. Meanwhile, the wild population in South China Sea away from restocking and massive aquaculture is seldom reported. In this study, the complete mitochondrial control regions (CR) of 98 individuals of Naozhou stock were determined and the data indicated that the haplotype diversity of Naozhou stock (Hd ＞ 98%) is higher than all the reported values. Inconsistent with previous conclusion by traditional methods, the non-significant Snn and FST owing to the strong gene flows (Nm), as well as the cluster tree without substructure reflected the lack of population differentiation in Large yellow croaker of Naozhou stock. Moreover, the demographic history was examined by using neutrality tests and mismatch distribution analysis, which revealed that the species obey the sudden expansion model. This result should be basic file for fisheries management and assessment of croaker.