Data_Sheet_1_Genetic Assessment of a Black Rockfish, Sebastes schlegelii, Stock Enhancement Program in Lidao Bay, China Based on Mitochondrial and Nuclear DNA Analysis.XLSX

The black rockfish Sebastes schlegelii is a commercially important fish species for marine fishery stock enhancement in Asia. This work aimed to evaluate the potential genetic impacts of releasing hatchery-reared juvenile black rockfish on wild stock in Lidao Bay, China. A partial sequence of the mitochondrial DNA (mtDNA) control region and 38 microsatellite DNA loci were used to assess the genetic impact. The haplotype diversity parameter (h) and nucleotide diversity parameter (π) in hatchery-released stock were 0.902 and 0.00483, respectively. The h values in wild stock before stock enhancement and the mixed stock after enhancement were 0.970 and 0.939 (p = 0.025), respectively, and the π values were 0.00581 and 0.00526 (p = 0.150), respectively. The mean effective number of alleles (Ae) in hatchery-released stock was 4.76, the mean polymorphism information content (PIC) was 0.674, the observed heterozygosity (Ho) was 0.668, and the expected heterozygosity (He) was 0.697. In wild stock before stock enhancement and the mixed stock after enhancement, the Ae, PIC, Ho, and He values were 6.01 and 5.82, 0.698 and 0.716, 0.709 and 0.741, and 0.735 and 0.754, respectively. These results indicated no marked decrease in the hatchery-released stock, although it displayed slightly lower levels of genetic diversity and heterozygosity than the wild stock. And the mixed stock after release exhibited similar genetic diversity to that of the wild stock before release. Accordingly, we propose that stock enhancement may not cause genetic diversity reduction on wild S. schlegelii stock in Lidao Bay over the short term. Whereas, discriminant analysis of principal components (DAPC) analysis identified three major clusters. The fixation index (FST) and analysis of molecular variance (AMOVA) also clearly showed low level but significant differentiations between the hatchery-released and wild stocks, and the wild stock before enhancement and the mixed stock after enhancement. Consequently, long-term genetic evaluation might be required.

黑石鲈（Sebastes schlegelii）是亚洲地区海洋渔业增殖放流的重要经济鱼类物种。本研究旨在评估人工繁育的稚龄黑石鲈放流对中国俚岛湾野生种群的潜在遗传影响。本研究采用线粒体DNA（mitochondrial DNA, mtDNA）控制区部分序列与38个微卫星DNA（microsatellite DNA）位点，对该遗传影响进行评估。繁育放流种群的单倍型多样性指数（h）与核苷酸多样性指数（π）分别为0.902与0.00483。增殖放流前野生种群及放流后混合种群的h值分别为0.970与0.939（p=0.025），π值分别为0.00581与0.00526（p=0.150）。繁育放流种群的平均有效等位基因数（Ae）为4.76，平均多态信息含量（polymorphism information content, PIC）为0.674，观测杂合度（observed heterozygosity, Ho）为0.668，期望杂合度（expected heterozygosity, He）为0.697。增殖放流前野生种群与放流后混合种群的Ae、PIC、Ho及He值分别为6.01与5.82、0.698与0.716、0.709与0.741，以及0.735与0.754。上述结果表明，尽管繁育放流种群的遗传多样性与杂合度略低于野生种群，但其并未出现显著下降。且放流后的混合种群遗传多样性与放流前的野生种群基本一致。据此，我们提出：短期内，增殖放流或不会对俚岛湾黑石鲈野生种群的遗传多样性造成显著降低。然而，主成分判别分析（discriminant analysis of principal components, DAPC）共鉴定出三个主要聚类簇。固定指数（fixation index, FST）与分子方差分析（analysis of molecular variance, AMOVA）同样清晰地显示，繁育放流种群与野生种群、放流前野生种群与放流后混合种群之间均存在低水平但显著的遗传分化。因此，可能需要开展长期的遗传评估工作。