(Table S1) Molecular analyses and morphological comparisons of deep-sea clams

Large vesicomyid clams are common inhabitants of sulphidic deep-sea habitats such as hydrothermal vents, hydrocarbon seeps and whale-falls. Yet, the species- and genus-level taxonomy of these diverse clams has been unstable due to insufficiencies in sampling and absence of detailed taxonomic studies that would consistently compare molecular and morphological characters. To clarify uncertainties about species-level assignments, we examined DNA sequences from mitochondrial cytochrome-c-oxidase subunit I (COI) in conjunction with morphological characters. New and published COI sequences were used to create a molecular database for 44 unique evolutionary lineages corresponding to species. Overall, the congruence between molecular and morphological characters was good. Several discrepancies due to synonymous species designations were recognized, and acceptable species names were rectified with published COI sequences in cases where morphological specimens were available. […]

大型蛤蜊类贝类是硫化型深海生境（如海底热液喷口、碳氢化合物渗漏和鲸落）的常见居民。然而，由于采样不足及缺乏能够一致性地比较分子和形态学特征的详细分类学研究，这些种类繁多的蛤蜊在物种和属的分类学上一直处于不稳定状态。为了阐明物种级别归属的不确定性，我们研究了来自线粒体细胞色素c氧化酶亚单位I（COI）的DNA序列，并结合形态学特征进行考察。利用新发表和已发表的COI序列，构建了一个包含44个独特进化谱系分子数据库，这些谱系对应于物种。总体而言，分子和形态学特征之间的一致性良好。识别出了一些由于同义词物种命名导致的差异，并在形态学标本可用的情况下，利用已发表的COI序列对可接受的物种名称进行了更正。