Genetic characterization of the artisanal mud crab fishery in Myanmar

Fish are important for food supply, especially in developing countries. In Southeast Asia, including Myanmar, the mud crab fishery is an important livelihood that represents a valuable source of income and food to coastal communities. However, the increasing demand for mud crab in domestic and international markets and poor management has generated concern about the status of this fishery across Southeast Asia. In this region, at least four species of mud crab in the genus Scylla are recognised but their correct identification and occurrence remain to be fully explained. Relying on accurate taxonomic identification of mud crab species represents the cornerstone of the successful implementation of management plans as life history biology and relative exploitation rates may vary by species due to gear susceptibility. Toward this aim, tissue samples from mud crabs were collected from four fishing communities of the Mergui archipelago, in the Tanintharyi region of southern Myanmar. All crab samples were DNA barcoded for species identification through sequencing. This study is the first genetic characterization of the mud crab fishery in Myanmar and revealed that Scylla olivacea was the only species found in the sampled fisheries of the Tanintharyi region. The populations studied across the Mergui archipelago did not show evidence of genetic structure, but gene flow appeared to be limited among conspecifics from neighbouring countries.鱼类对于粮食供应至关重要，尤其在发展中国家。在包括缅甸在内的东南亚地区，泥蟹（mud crab）捕捞业是沿海社区的重要生计来源，同时也是其收入与食物的宝贵来源。然而，国内外市场对泥蟹日益增长的需求以及管理不善的现状，引发了学界对东南亚地区该捕捞业资源现状的担忧。该区域目前已确认青蟹属（Scylla）下至少存在四种泥蟹物种，但针对这些物种的准确鉴定方法与实际分布情况仍有待全面阐明。由于不同物种对捕捞渔具的敏感性存在差异，其生活史生物学特征与相对捕捞率也会因物种而异，因此对泥蟹物种开展准确的分类学鉴定，是成功实施渔业管理计划的核心基石。为此，研究人员从缅甸南部丹那沙林（Tanintharyi）地区丹老群岛（Mergui archipelago）的四个捕捞社区采集了泥蟹组织样本。所有蟹类样本均通过测序技术完成DNA条形码（DNA barcode）物种鉴定。本研究是缅甸首次针对当地泥蟹捕捞业开展的遗传学特征解析，结果显示丹那沙林地区的采样捕捞区域内仅发现榄青蟹（Scylla olivacea）一个物种。丹老群岛的研究种群未表现出显著的遗传结构（genetic structure），但邻近国家的同种个体间的基因流（gene flow）似乎受到限制。