Treleven Charles R, Kishe Mary A, Silas Mathew O, Ngatunga Benjamin P, Kuboja Bigeyo N, Mgeleka Said S, Taylor Amy L, Elsmore Megan A M, Healey Amy J E, Sauer Warwick H H, Shaw Paul W, McKeown Niall J
Department of Life Sciences Aberystwyth University Aberystwyth UK.
Fisheries Research Institute (TAFIRI) Dar es Salaam Tanzania.
Ecol Evol. 2024 Apr 4;14(4):e11205. doi: 10.1002/ece3.11205. eCollection 2024 Apr.
(Gray, 1849), abundant in the South-West Indian Ocean (SWIO), constitutes a vital resource for both subsistence and commercial fisheries. However, despite this socioeconomic importance, and recent indications of overfishing, little is known about the population structure of in the region. To inform sustainable management strategies, this study assessed the spatio-temporal population structure and genetic variability of at 20 sites in the SWIO (Kenya, Tanzania, Mozambique, Madagascar, Mauritius, Rodrigues, and the Seychelle Islands) by complementary analysis of mitochondrial DNA (mtDNA) noncoding region (NCR) sequences and microsatellite markers. MtDNA analysis revealed a shallow phylogeny across the region, with demographic tests suggesting historic population fluctuations that could be linked to glacial cycles. Contrary to expectations, NCR variation was comparable to other mtDNA regions, indicating that the NCR is not a hypervariable region. Both nuclear and mtDNA marker types revealed a lack of genetic structure compatible with high gene flow throughout the region. As adults are sedentary, this gene flow likely reflects connectivity by paralarval dispersal. All samples reported heterozygote deficits, which, given the overall absence of structure, likely reflect ephemeral larval recruitment variability. Levels of mtDNA and nuclear variability were similar at all locations and congruent with those previously reported for harvested Octopodidae, implying resilience to genetic erosion by drift, providing current stock sizes are maintained. However, as stocks in the SWIO represent a single, highly connected population, fisheries may benefit from additional management measures, such as rotational closures aligned with paralarval ecology and spanning geopolitical boundaries.
（格雷，1849年）在西南印度洋（SWIO）数量丰富，是自给性渔业和商业渔业的重要资源。然而，尽管具有这种社会经济重要性，且近期有过度捕捞的迹象，但对该区域[物种名称未给出]的种群结构却知之甚少。为了为可持续管理策略提供依据，本研究通过对线粒体DNA（mtDNA）非编码区（NCR）序列和微卫星标记进行互补分析，评估了西南印度洋20个地点（肯尼亚、坦桑尼亚、莫桑比克、马达加斯加、毛里求斯、罗德里格斯岛和塞舌尔群岛）[物种名称未给出]的时空种群结构和遗传变异性。mtDNA分析揭示了该区域内的系统发育关系较浅，人口统计测试表明历史上的种群波动可能与冰川周期有关。与预期相反，NCR变异与其他mtDNA区域相当，表明NCR不是一个高变区。核标记和mtDNA标记类型均显示缺乏与整个区域高基因流相匹配的遗传结构。由于成年个体定居，这种基因流可能反映了幼体前期扩散的连通性。所有样本均报告了杂合子缺失，鉴于总体上缺乏结构，这可能反映了短暂的幼体补充变异性。所有地点的mtDNA和核变异性水平相似，且与先前报道的捕捞八腕总科的水平一致，这意味着只要维持当前种群规模，就能抵御遗传漂变导致的遗传侵蚀。然而，由于西南印度洋的[物种名称未给出]种群代表一个单一的、高度连通的种群，渔业可能会受益于额外的管理措施，例如与幼体前期生态学一致且跨越地缘政治边界的轮流禁渔。
