The speckled shrimp Metapenaeus monoceros is a commercially important penaeid shrimp in the Indo-West Pacific region including Bangladesh. Phylogenetics of penaeid shrimps is still a debatable issue, and molecular variation within the species is large. This study focused on the phylogeography of M. monoceros, including an assessment of the phylogenetic relationships among seven other Metapenaeus species by assessing sequence variation in three mitochondrial markers, the cytochrome oxidase subunit 1 (CO1), control region (CR) and 16S rRNA (16S). In addition, the mitochondrial variation along the Bangladesh coastline was analysed. The mitochondrial variation has a clear geographical pattern with two distinct evolutionary lineages, one found in the western Indian Ocean and the Mediterranean Sea and the second in the eastern Indian Ocean. A phylogenetic analysis of Metapenaeus based on the three markers revealed polyphyletic relationships within the genus and that the taxonomy needs revision. The mtDNA variation in Metapenaeus monoceros in Bangladesh presents a single population (AMOVA, F_ST and Φ_ST p > .05), which started to expand around 467 (CI: 186–753) kyr ago, and is characterized by a large number of closely related haplotypes. The study could be used to improve the management and conservation of the shrimp fishery in the region.

中文翻译：

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Metapenaeus monoceros (Decapoda, Penaeidae) 的线粒体 DNA 变异揭示了孟加拉国内的高遗传变异，在印度洋具有不同的谱系

斑节对虾Metapenaeus monoceros是包括孟加拉国在内的印度-西太平洋地区具有重要商业价值的对虾。对虾的系统发育学仍然是一个有争议的问题，物种内的分子变异很大。这项研究的重点是M. monoceros的系统地理学，包括评估其他七种Metapenaeus之间的系统发育关系通过评估三种线粒体标记物的序列变异，细胞色素氧化酶亚基 1 (CO1)、控制区 (CR) 和 16S rRNA (16S)。此外，还分析了孟加拉国海岸线的线粒体变异。线粒体变异具有清晰的地理模式，具有两种不同的进化谱系，一种在西印度洋和地中海中发现，另一种在东印度洋中发现。基于三个标记对Metapenaeus的系统发育分析揭示了该属内的多系关系，并且分类学需要修订。孟加拉国Metapenaeus monoceros的 mtDNA 变异呈现单一种群（AMOVA、F _ST和 Φ _ST p > .05)，大约在 467 (CI: 186–753) kyr 之前开始扩展，其特征是大量密切相关的单倍型。该研究可用于改善该地区对虾渔业的管理和保护。