Weak population structure of the Spot-tail shark Carcharhinus sorrah and the Blacktip shark C. limbatus along the coasts of the Arabian Peninsula, Pakistan and South Africa

The increase in demand for shark meat and fins has placed shark populations worldwide under high fishing pressure. In the Arabian region, the Spot-tail shark Carcharhinus sorrah and the Blacktip shark Carcharhinus limbatus are among the most exploited species. In this study we investigated the population genetic structure of C. sorrah (n= 327) along the coasts of the Arabian Peninsula and of C. limbatus (n= 525) along the Arabian coasts, Pakistan and KwaZulu-Natal, South Africa using microsatellite markers (15 and 11 loci respectively). Our findings support weak population structure in both species. Carcharhinus sorrah exhibited a fine structure, subdividing the area into three groups. The first group comprises all samples from Bahrain, the second from the UAE and Yemen and the third from Oman. Similarly, C. limbatus exhibited population subdivision into three groups. The first group, comprising samples from Bahrain and Kuwait, was highly differentiated from the second and third group,...鲨鱼肉与鱼鳍的需求持续攀升，致使全球鲨鱼种群面临高强度捕捞压力。在阿拉伯地区，斑尾真鲨（Spot-tail shark, Carcharhinus sorrah）与黑背真鲨（Blacktip shark, Carcharhinus limbatus）为受开发利用程度最高的物种之一。本研究采用微卫星标记（分别包含15个和11个位点），对阿拉伯半岛沿岸的斑尾真鲨（样本量n=327），以及阿拉伯沿岸、巴基斯坦与南非夸祖鲁-纳塔尔省沿岸的黑背真鲨（样本量n=525）的种群遗传结构开展了调查。研究结果表明，两个物种均呈现较弱的种群遗传结构分化。斑尾真鲨存在精细种群结构，可将其分布区域划分为三个类群：第一类群涵盖所有采自巴林的样本，第二类群包含采自阿拉伯联合酋长国（UAE）与也门的样本，第三类群则来自阿曼。与之类似，黑背真鲨的种群也被划分为三个类群：第一类群包含采自巴林与科威特的样本，其与第二、第三类群的遗传分化程度极高……