College of Fisheries, & Key Laboratory of Evolution and Marine Biodiversity of Ministry of Education, Ocean University of China, Qingdao, 266003, China.
Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
BMC Microbiol. 2024 Jan 19;24(1):27. doi: 10.1186/s12866-024-03190-y.
As unicellular eukaryotes, ciliates are an indispensable component of micro-ecosystems that play the role of intermediate nutrition link between bacteria or algae and meiofauna. Recent faunistic studies have revealed many new taxa of hypotrich ciliates, indicating their diversity is greater than previously thought. Here we document an undescribed form isolated from an artificial brackish water pond in East China. Examination of its morphology, ontogenesis and molecular phylogeny suggests that it represents a new species.
The morphology and morphogenesis of the new brackish-water deviatid ciliate, Heterodeviata nantongensis nov. sp., isolated from Nantong, China, were investigated using live observations and protargol staining. The diagnostic traits of the new species include three frontal cirri, one buccal cirrus, one or two parabuccal cirri, an inconspicuous frontoventral cirral row of four to six frontoventral cirri derived from two anlagen, three left and two right marginal rows, two dorsal kineties, dorsal kinety 1 with 9-14 dikinetids and dorsal kinety 2 with only two dikinetids, and one to three caudal cirri at the rear end of dorsal kinety 1. Its main morphogenetic features are: (i) the old oral apparatus is completely inherited by the proter except undulating membranes, which are reorganized in situ; (ii) anlagen for marginal rows and the left dorsal kinety develop intrakinetally in both proter and opisthe; (iii) dorsal kinety 2 is generated dorsomarginally; (iv) five cirral anlagen are formed in both proter and opisthe; (v) in the proter, anlagen I and II very likely originate from the parental undulating membranes and the buccal cirrus, respectively, anlage III from anterior parabuccal cirrus, anlage IV originates from the parental frontoventral cirri and anlage V from the innermost parental right marginal row; and (vi) anlagen I-IV of the opisthe are all generated from oral primordium, anlage V from the innermost parental right marginal row. Phylogenetic analyses based on SSU rRNA gene sequence data were performed to determine the systematic position of the new taxon.
The study on the morphology, and ontogenesis of a new brackish-water taxon increases the overall knowledge about the biodiversity of this ciliate group. It also adds to the genetic data available and further provides a reliable reference for environmental monitoring and resource investigations.
纤毛虫作为单细胞真核生物，是微生物生态系统中不可或缺的组成部分，在细菌或藻类与小型后生动物之间起着中间营养联系的作用。最近的动物区系研究揭示了许多新的缘毛目纤毛虫分类群，表明它们的多样性比以前认为的要大。在这里，我们记录了一种来自中国东部人工咸水池塘的未描述形式。通过形态学、个体发生和分子系统发育的研究，表明它代表了一个新物种。
对来自中国南通的新的咸水偏离纤毛虫 Heterodeviata nantongensis nov. sp. 的形态和个体发生进行了研究，使用活观察和蛋白银染色。新物种的鉴别特征包括三个额前纤毛、一个口纤毛、一个或两个副口纤毛、一个不明显的额腹侧纤毛列，由两个原基衍生的四个到六个额腹侧纤毛组成，三个左侧和两个右侧缘毛列，两个背侧动基体，背侧动基体 1 有 9-14 个双联体，背侧动基体 2 只有两个双联体，以及一个或三个位于背侧动基体 1 后端的尾纤毛。其主要的个体发生特征是：（i）老的口器完全由前体继承，除了重新原位重组的波动膜外；（ii）缘毛列和左侧背侧动基体的原基在前后体中都是内动基体发育的；（iii）背侧动基体 2 是从背缘产生的；（iv）前后体中都形成了五个纤毛原基；（v）在前体中，原基 I 和 II 很可能分别来自亲代的波动膜和口纤毛，原基 III 来自前副口纤毛，原基 IV 来自亲代的额腹侧纤毛，原基 V 来自最内的亲代右侧缘毛列；以及（vi）后体的原基 I-IV 都是从口原基生成的，原基 V 是从最内的亲代右侧缘毛列生成的。基于 SSU rRNA 基因序列数据的系统发育分析确定了新分类群的系统位置。
对一个新的咸水生物种的形态和个体发生的研究增加了对这一纤毛虫群体生物多样性的总体认识。它还增加了可用的遗传数据，并进一步为环境监测和资源调查提供了可靠的参考。
