Data from: The genetic structure of Nautilus pompilius populations surrounding Australia and the Philippines

Understanding the distribution of genetic diversity in exploited species is fundamental to successful conservation. Genetic structure and the degree of gene flow among populations must be assessed to design appropriate strategies to prevent the loss of distinct populations. The cephalopod Nautilus pompilius is fished unsustainably in the Philippines for the ornamental shell trade and has limited legislative protection, despite the species’ recent dramatic decline in the region. Here, we use 14 microsatellite markers to evaluate the population structure of N. pompilius around Australia and the Philippines. Despite their relative geographical proximity, Great Barrier Reef individuals are genetically isolated from Osprey Reef and Shark Reef in the Coral Sea (FST=0.312, 0.229, respectively). Conversely, despite the larger geographical distances between the Philippines and west Australian reefs, samples display a small degree of genetic structure (FST=0.015). Demographic scenarios modelled using approximate Bayesian computation analysis indicate that this limited divergence is not due to contemporary gene flow between the Philippines and west Australia. Instead, present-day genetic similarity can be explained by very limited genetic drift that has occurred due to large average effective population sizes that persisted at both locations following their separation. The lack of connectivity among populations suggests that immigrants from west Australia would not facilitate natural recolonization if Philippine populations were fished to extinction. These data help to rectify the paucity of information on the species’ biology currently inhibiting their conservation classification. Understanding population structure can allow us to facilitate sustainable harvesting, thereby preserving the diversity of genetically distinct stocks.解析受开发利用物种的遗传多样性分布格局，是成功开展物种保护工作的核心前提。需对种群遗传结构及种群间基因流动程度开展评估，方可制定合理策略以避免独特种群的丧失。头足类物种珍珠鹦鹉螺（Nautilus pompilius）因装饰性贝壳贸易在菲律宾遭到过度捕捞，且该物种在当地近年种群数量急剧下降的情况下，法定保护力度仍十分有限。本研究利用14个微卫星（microsatellite）标记，对澳大利亚及菲律宾周边海域的珍珠鹦鹉螺种群结构进行解析。尽管地理距离相对较近，大堡礁的珍珠鹦鹉螺个体与珊瑚海的鹰礁、鲨鱼礁种群间存在显著遗传隔离（对应FST值分别为0.312、0.229）。与之相反，尽管菲律宾与西澳大利亚礁群间的地理距离更远，但采样样本仅表现出微弱的遗传分化（FST值为0.015）。采用近似贝叶斯计算（approximate Bayesian computation）分析构建的种群历史动态模型显示，这种微弱的遗传分化并非源于菲律宾与西澳大利亚种群间的当代基因交流。反之，当前种群间的遗传相似性，可归因于两种群分离后各自维持的较大平均有效种群规模（effective population size），使得遗传漂变发生的程度极为有限。种群间缺乏连通性的结果表明，若菲律宾种群因捕捞灭绝，西澳大利亚种群的个体无法通过自然扩散实现种群重建。本研究数据弥补了当前制约该物种保护等级评估的生物学信息匮乏问题。明晰种群结构可助力我们推行可持续捕捞方案，从而保护具有独特遗传特征的种群资源多样性。