Hexactinellid sponges are important members of deep-sea benthic ecosystems because they provide available hard substrate habitats for filter-feeding invertebrates. However, symbioses between hexactinellid sponges and their symbionts are poorly known. Zoantharians associated with hexactinellid sponges have been reported widely from deep-sea marine ecosystems, either on the bodies or stalks of hexactinellid sponges. Despite these records, there has been a lack of research on their diversity and phylogenetic relationships. In this study, 20 specimens associated with amphidiscophoran and hexasterophoran sponges were collected from the waters of Australia and Japan in the Pacific, and from Curaçao in the southern Caribbean, and these were examined in addition to museum specimens. Based on molecular phylogenetic analyses and morphological observations, we formally describe two new genera and three new species of Zoantharia and report several previously described species. The results suggest at least two independent origins for the symbioses between hexactinellid sponges and zoantharians. Our results demonstrate that the diversity of hexactinellid sponge-associated zoantharians is much higher than has been previously thought. The new taxa described in this work further reconfirm that the deep-sea harbours high levels of undescribed zoantharian diversity.

中文翻译：

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玻璃海绵相关环斑动物的进化和系统发育，并描述了两个新属和三个新种

Hexactinellid 海绵是深海底栖生态系统的重要成员，因为它们为滤食性无脊椎动物提供了可用的硬质基质栖息地。然而，hexactinellid 海绵与其共生体之间的共生关系却鲜为人知。与 hexactinellid 海绵有关的 Zoantharians 在深海海洋生态系统中被广泛报道，无论是在 hexactinellid 海绵的身体还是茎上。尽管有这些记录，但仍缺乏对其多样性和系统发育关系的研究。在这项研究中，从太平洋的澳大利亚和日本水域以及南加勒比海的库拉索岛收集了 20 个与两栖动物和六角动物海绵相关的标本，除博物馆标本外，还对这些标本进行了检查。基于分子系统发育分析和形态观察，我们正式描述了 Zoantharia 的两个新属和三个新物种，并报告了几个先前描述的物种。结果表明，hexactinellid 海绵和 zoantharians 之间的共生关系至少有两个独立的起源。我们的研究结果表明，六线形海绵相关的环虫的多样性比以前认为的要高得多。这项工作中描述的新分类群进一步再次证实，深海蕴藏着高水平的未描述的动物多样性。我们的研究结果表明，六线形海绵相关的环虫的多样性比以前认为的要高得多。这项工作中描述的新分类群进一步再次证实，深海蕴藏着高水平的未描述的动物多样性。我们的研究结果表明，六线形海绵相关的环虫的多样性比以前认为的要高得多。这项工作中描述的新分类群进一步再次证实，深海蕴藏着高水平的未描述的动物多样性。