Smith Susan A, Song Wen, Gavrilova Nelly A, Kurilov Alexander V, Liu Weiwei, McManus George B, Santoferrara Luciana F
Department of Marine Sciences, University of Connecticut, Groton, Connecticut, 06340, USA.
Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
J Eukaryot Microbiol. 2018 May;65(3):400-411. doi: 10.1111/jeu.12485. Epub 2017 Dec 3.
A tintinnid ciliate isolated from waters of the Thames River (Connecticut, USA) is described through combined in vivo observation, protargol impregnation, and phylogenetic analysis. The novel genus Dartintinnus and its type species, D. alderae are distinct from established tintinnid taxa by a lorica that collapses on both anterior and posterior ends. Dartintinnus is placed in the family Eutintinnidae based on a hyaline, elongated lorica opened at both ends, a ciliary pattern including a ventral kinety, at least one dorsal kinety, and right, left and lateral fields, and a sister relationship with Eutintinnus in gene trees. Main differences between D. alderae and Eutintinnus species include a 5.5-6.5% divergence in the small subunit rRNA gene, the geometry of the lorica (resembling an isosceles tetrahedron when collapsed vs. a cylinder, respectively), the number of macronuclear nodules (two vs. four), and the number of dorsal kineties (one vs. usually two). Considering the features of the new genus, we improve the diagnosis of the family Eutintinnidae, including the presence of a lateral ciliary field that had been overlooked in some Eutintinnus species. This work exemplifies the potential for novel diversity, even in these relatively well-studied protists, and the importance of an integrated approach for the description of tintinnid taxa.
通过体内观察、原银浸染和系统发育分析相结合的方法，对从美国康涅狄格州泰晤士河水域分离出的一种铃壳纤毛虫进行了描述。新属Dartintinnus及其模式种D. alderae与已确立的铃壳类分类群不同，其外壳在前端和后端都会塌陷。基于两端开口的透明细长外壳、包括腹动基列、至少一个背动基列以及右、左和侧动基列区的纤毛模式，以及在基因树中与真铃壳虫属的姐妹关系，Dartintinnus被归入真铃壳虫科。D. alderae与真铃壳虫属物种的主要区别包括小亚基rRNA基因5.5 - 6.5%的差异、外壳的几何形状（塌陷时分别类似于等腰四面体与圆柱体）、大核结节的数量（两个与四个）以及背动基列的数量（一个与通常两个）。考虑到新属的特征，我们改进了真铃壳虫科的诊断，包括一些真铃壳虫属物种中被忽视的侧纤毛区的存在。这项工作例证了即使在这些研究相对充分的原生生物中，仍存在新的多样性，以及采用综合方法描述铃壳类分类群的重要性。
