Carmen Campos Panisse 3, Puerto de Santa María, Spain.
Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA.
J Eukaryot Microbiol. 2022 Jul;69(4):e12920. doi: 10.1111/jeu.12920. Epub 2022 May 12.
The Gonyaulacales includes some of the most intensely investigated genera of harmful dinoflagellates. The knowledge of the evolutionary relationships is necessary, but incomplete because genera such as Schuettiella have not been studied by contemporary methods. The morphology and molecular phylogeny of type species of the genus Schuettiella, S. mitra, have been investigated from Brazil. The first scanning electron micrographs reveal a distinctive thecal ornamentation with sunken stripes and rows with exclamation mark-shaped pores in the postcingular plates. The Kofoidean plate formula Po, 2', 1a, 6″ is re-interpreted as Po, 3', 1a, 5″, after considering the narrow mid-ventral plate as homologous to the first apical plate, although it does not reach the apex. In the rRNA gene phylogenies, the sequences of S. mitra clustered as an independent lineage closely related to the globular and planktonic Protoceratiaceae (Ceratocorys, Pentaplacodinium, Protoceratium) and the laterally compressed benthic genus Carinadinium (formerly Thecadinium). Schuettiella and Carinadinium are considered members of the Protoceratiaceae. The possession of a single anterior intercalary plate is an apomorphic trait of this family. This reinforces the value of the number of intercalary plates as a diagnostic character for the classification of the gonyaulacalean families despite the differences in the general appearance.
旋沟藻目包含一些研究最为深入的有害甲藻属。了解进化关系是必要的，但并不完整，因为像 Schuettiella 这样的属尚未通过现代方法进行研究。本文从巴西调查了 Schuettiella 属的模式种 Schuettiella mitra 的形态和分子系统发育。首次扫描电镜照片显示，在后尾板上有独特的壳纹装饰，有凹陷的条纹和带有感叹号形状孔的行。Kofoidian 板公式 Po, 2', 1a, 6″被重新解释为 Po, 3', 1a, 5″，因为考虑到狭窄的中腹板与第一个顶片同源，尽管它没有到达顶点。在 rRNA 基因系统发育中，S. mitra 的序列作为一个独立的谱系聚类，与球形和浮游性原甲藻科（Ceratocorys、Pentaplacodinium、Protoceratium）和侧向压缩的底栖属 Carinadinium（以前的 Thecadinium）密切相关。Schuettiella 和 Carinadinium 被认为是原甲藻科的成员。单一的前间插片是该科的一个特化特征。这加强了间插片数量作为 Gonyaulacales 科分类的诊断特征的价值，尽管在外观上存在差异。
