Geographical and oceanographic processes have influenced the speciation of marine organisms. Cone snails are marine mollusks that show high levels of endemism and a wide distributional range across the Indian and Pacific Oceans. Discontinuities in distributions caused by biogeographic barriers can affect genetic connectivity. Here we analysed the connectivity within Conus litteratus using samples from the Lakshadweep archipelago (Arabian Sea, Indian Ocean) and from the Pacific Ocean. Maximum likelihood analyses based on the mitochondrial cytochrome C oxidase subunit I (COI) and on the non-coding 16S ribosomal RNA (16S rRNA) genes revealed cryptic diversity within C. literatus occupying distinct oceanographic regions. The intraspecific genetic distances between the two distinct clades of C. literatus from the Arabian Sea and the Pacific Ocean ranged from 7.4% to 7.6% for COI and from 2.4% to 2.8% for 16S rRNA genes, which is larger than the threshold limit for interspecific differentiation. The haplotype network analysis also corroborated the existence of two different lineages within C. litteratus. The detected genetic discontinuities reflect the effect of the Sunda shelf biogeographic barrier on the allopatric divergence of C. litteratus.

中文翻译：

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巽他大陆架生物地理屏​​障在印度-太平洋地区Conus litteratus（腹足纲：Conidae）隐秘分化中的作用

地理和海洋过程影响了海洋生物的物种形成。锥形蜗牛是海洋软体动物，具有高度的特有性，分布范围广泛，遍布印度洋和太平洋。生物地理障碍引起的分布不连续性可能会影响遗传连通性。在这里，我们使用来自拉克沙群岛（阿拉伯海、印度洋）和太平洋的样本分析了芋螺内部的连通性。基于线粒体细胞色素 C 氧化酶亚基 I (COI) 和非编码 16S 核糖体 RNA (16S rRNA) 基因的最大似然分析揭示了 C. literatus 占据不同海洋区域的神秘多样性。来自阿拉伯海和太平洋的两个不同分支之间的 COI 基因的种内遗传距离为 7.4% 至 7.6%，16S rRNA 基因的种内遗传距离为 2.4% 至 2.8%，这大于种间分化。单倍型网络分析还证实了 C. litteratus 中存在两个不同的谱系。检测到的遗传不连续性反映了巽他大陆架生物地理屏​​障对 C. litteratus 异域分化的影响。