In this study, we conduct a morphological integrative analysis, using traditional techniques and micro-computed tomography imaging, on Septibranchia species. Specimens deposited in malacological collections and samples collected aboard the research vessels Puerto Deseado and Austral off Mar del Plata (~36°S), San Jorge Gulf (~46°), and Marine Protected Area Namuncurá/Burdwood Bank area (~54°S), at depths ranging from 200 to 3000 m, are the subjects of this study. Seven species were identified, including Cardiomya cleryana (d’Orbigny, 1846), Cardiomya knudseni (Allen & Morgan, 1981), Lyonsiella cf. fragilis Allen & Turner, 1974, and Cetoconcha spinulosa (Thiele, 1912), previously found in the study area. Cardiomya fragilissima (E. A. Smith, 1885), an Antarctic/sub-Antarctic species, extends its distribution up to 36°S. Two new species, Cetoconcha gigas sp. nov. and Lyonsiella tentaculata sp. nov., are described. A lectotype is designated for Pholadomya adelaidis Hedley, 1916 and a neotype for Sphenia cleryana d’Orbigny, 1846. A detailed description of the morphological characters of each species and genus, along with insights into their geographical and bathymetric distribution, are provided. The micro-computed tomography analysis of Cardiomya cleryana, Cardiomya fragilissima, and Cetoconcha spinulosa contributed to a detailed anatomical inspection and revealed the presence of muscle bundles associated with the anterior portion of the visceral mass in the scanned specimens.

中文翻译：

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使用传统工具和微型计算机断层扫描对西南大西洋深水区的肉食性双壳类进行分类


在这项研究中，我们利用传统技术和微型计算机断层扫描成像对七鳃亚属物种进行形态学综合分析。标本存放于马德普拉塔（~36°S）、圣豪尔赫湾（~46°）和海洋保护区 Namuncurá/Burdwood Bank 区域（~54°S） ），深度范围为 200 至 3000 m，是本研究的主题。鉴定出七个物种，包括 Cardiomya cleryana (d'Orbigny, 1846)、Cardiomya knudseni (Allen & Morgan, 1981)、Lyonsiella cf. fragilis Allen & Turner, 1974, 和 Cetoconcha spinulosa (Thiele, 1912)，先前在研究区域发现。 Cardiomya fragilissima (EA Smith, 1885) 是一种南极/亚南极物种，其分布范围延伸至南纬 36°。两个新种，Cetoconcha gigas sp。十一月和 Lyonsiella tentaculata sp。十一月，进行了描述。 1916 年指定了 Pholadomya adelaidis Hedley 的选型，1846 年指定了 Sphenia cleryana d'Orbigny 的新型。提供了每个物种和属的形态特征的详细描述，以及对其地理和测深分布的见解。对 Cardiomya cleryana、Cardiomya fragilissima 和 Cetoconcha spinulosa 的显微计算机断层扫描分析有助于进行详细的解剖检查，并揭示扫描标本中与内脏肿块前部相关的肌束的存在。