Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology, 181 Ipsingil, Jeongeup 56212, Republic of Korea.
Ifremer, LER BO, Station de Biologie Marine, Place de la Croix, BP40537, F-29185 Concarneau Cedex, France.
Protist. 2020 Nov;171(5):125759. doi: 10.1016/j.protis.2020.125759. Epub 2020 Sep 1.
In the current circumscription, the Thoracosphaeraceae comprise all dinophytes exhibiting calcified coccoid cells produced during their life-history. Species hitherto assigned to Ensiculifera and Pentapharsodinium are mostly based on the monadoid stage of life-history, while the link to the coccoid stage (occasionally treated taxonomically distinct) is not always resolved. We investigated the different life-history stages and DNA sequence data of Ensiculifera mexicana and other species occurring in samples collected from all over the world. Based on concatenated ribosomal RNA gene sequences Ensiculiferaceae represented a distinct peridinalean branch, which showed a distant relationship to other calcareous dinophytes. Both molecular and morphological data (particularly of the coccoid stage) revealed the presence of three distinct clades within Ensiculiferaceae, which may include other dinophytes exhibiting a parasitic life-history stage. At a higher taxonomic level, Ensiculiferaceae showed relationships to parasites and endosymbionts (i.e., Blastodinium and Zooxanthella) as well as to dinophytes harbouring diatoms instead of chloroplasts. These unexpected phylogenetic relationships are corroborated by the presence of five cingular plates in all such taxa, which differs from the six cingular plates of most other Thoracosphaeraceae. We herein describe Ensiculiferaceae, emend the descriptions of Ensiculifera and Pentapharsodinium, erect Matsuokaea and provide several new combinations at the species level.
在当前的分类中，Thoracosphaeraceae 包括所有在其生活史中产生钙化球形细胞的沟鞭藻类。迄今归入 Ensiculifera 和 Pentapharsodinium 的物种主要基于生活史的单体阶段，而与球形阶段（偶尔在分类上被视为不同）的联系并不总是确定的。我们研究了 Ensiculifera mexicana 及其他在世界各地采集的样本中出现的物种的不同生活史阶段和 DNA 序列数据。基于核糖体 RNA 基因序列的串联，Ensiculiferaceae 代表了一个独特的 Peridiniales 分支，与其他钙质沟鞭藻具有较远的关系。分子和形态数据（特别是球形阶段）揭示了 Ensiculiferaceae 内存在三个不同的分支，其中可能包括其他表现出寄生生活史阶段的沟鞭藻。在更高的分类水平上，Ensiculiferaceae 与寄生虫和内共生体（即 Blastodinium 和 Zooxanthella）以及含有硅藻而不是叶绿体的沟鞭藻有关。所有这些类群都具有五个环带板，这与大多数其他 Thoracosphaeraceae 的六个环带板不同，这一事实证实了这些意外的系统发育关系。我们在此描述了 Ensiculiferaceae，修正了 Ensiculifera 和 Pentapharsodinium 的描述，建立了 Matsuokaea，并在种级水平上提供了几个新的组合。
