Corals (Metazoa; Cnidaria; Anthozoa) have recently been shown to play host to a widespread and diverse group of intracellular symbionts of the phylum Apicomplexa. These symbionts, colloquially called “corallicolids”, are mostly known through molecular analyses, and no formal taxonomy has been proposed. Another apicomplexan, Gemmocystis cylindrus (described from the coral Dendrogyra cylindrus), may be related to corallicolids, but lacks molecular data. Here, we isolate and describe motile trophozoite (feeding) corallicolids cells using microscopic (light, SEM, and TEM) and molecular phylogenetic analysis to provide the basis for a formal description. Phylogenetic analyses using nuclear and plastid rRNA operons, and three mitochondrial protein sequences derived from single cell transcriptomes, all confirm that these organisms fall into a discrete deep-branching clade within the Apicomplexa not closely related to any known species or major subgroup. As a result, we assign this clade to a new order, Corallicolida ord. nov., and family, Corallicolidae fam. nov. We describe a type species, Corallicola aquarius gen. nov. sp. nov. from its Rhodactis sp. host, and also describe a second species, Anthozoaphila gnarlus gen. nov. sp. nov., from the coral host Madracis mirabilis. Finally, we propose reassigning the incertae sedis taxon G. cylindrus from the order Agamococcidiorida to the Corallicolida, based on similarities in morphology and host localization to that of the corallicolids.

中文翻译：

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珊瑚Apicomplexan Symbionts 的分类，包括Corallicolida ord。十一月，Gemocystis 属的重新分配，以及新物种 Corallicola aquarius gen 的描述。十一月 sp. 十一月 和 Anthozoaphila gnarlus gen。十一月 sp. 十一月

珊瑚（后生动物；刺胞动物；珊瑚虫）最近被证明是 Apicomplexa 门的广泛多样的细胞内共生群的宿主。这些共生体，通俗地称为“珊瑚胶体”，主要通过分子分析而为人所知，并且尚未提出正式的分类法。另一种顶端复合体，Gemocystis cylindrus（描述自珊瑚Dendrogyra cylindrus)，可能与corallicolids有关，但缺乏分子数据。在这里，我们使用显微（光、SEM 和 TEM）和分子系统发育分析分离和描述活动的滋养体（摄食）corallicolids 细胞，以提供正式描述的基础。使用核和质体 rRNA 操纵子以及源自单细胞转录组的三个线粒体蛋白序列进行的系统发育分析都证实，这些生物属于顶复群内一个离散的深分支进化枝，与任何已知物种或主要亚群没有密切关系。因此，我们将这个进化枝分配给一个新的命令 Corallicolida ord。十一月，和家庭，珊瑚科家族。十一月 我们描述了一个类型的物种，Corallicola 水瓶座根。十一月 sp. 十一月 从它的Rhodactissp. 主机，还描述了一个物种，Anthozoaphila gnarlus根。十一月 sp. 11 月，来自珊瑚寄主Madracis mirabilis。最后，我们建议重新分配 incertae sedis 分类群G。 cylindrus基于在形态学和主机定位于所述corallicolids的相似之处Agamococcidiorida为了将Corallicolida。