Sclerolinum is a small genus of Siboglinidae (Annelida) living in an obligate mutualistic association with thiotrophic bacteria as adults. Its taxonomic position, based on morphology, has been controversial; however, molecular data point to a sister taxa relationship with vestimentiferans. 16S rRNA gene sequencing and comparative morphology revealed that the studied population from deep-sea hydrocarbon seeps of the Gulf of Mexico belongs to Sclerolinum contortum known from the Arctic Sea. Since no anatomical and microanatomical studies have been published yet, we conducted such a study on S. contortum using serial sectioning and light and transmission electron microscopy. We show that the Sclerolinum body, divided into a head, trunk, and opisthosoma, is very similar to that of the vestimentiferans, and therefore we propose that the body regions are homologous in both taxa.

中文翻译：

---

墨西哥湾 Contortum（Siboglindae，Annelida）的形态学、显微解剖学和序列数据


硬核菌是 Siboglinidae (Annelida) 的一个小属，成虫时与硫营养菌呈专性共生关系。它基于形态学的分类地位一直存在争议。然而，分子数据表明与 Vestimentiferans 存在姐妹分类群关系。 16S rRNA基因测序和比较形态学表明，所研究的来自墨西哥湾深海碳氢化合物渗漏物的种群属于北冰洋的Scleolinum contortum。由于尚未发表解剖学和显微解剖学研究，我们使用连续切片以及光学和透射电子显微镜对 S. contortum 进行了这样的研究。我们发现硬核菌的身体分为头部、躯干和后体，与前体动物的身体非常相似，因此我们认为这两个类群的身体区域是同源的。