AUTHOR=Wu Zehao , Liu Mingjian , Ye Tingting , Zhao Xuetong , Wu Fan , Jiang Yaohan , Chen Xiangrui 

TITLE=New contributions to the taxonomy and phylogeny of the ciliate genus Pleuronema (Ciliophora, Scuticociliatia), with descriptions of two new species collected from the subtropical coastal wetlands in China

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1320684

DOI=10.3389/fmars.2023.1320684

ISSN=2296-7745

ABSTRACT=Ciliates of the genus Pleuronema Dujardin, 1841 are a speciose and ubiquitous group. Recent studies suggest that there could be a sizable amount of undiscovered species diversity. In the present study, two new Pleuronema species have been isolated from subtropical coastal waters of China, and characterized using morphological and taxonomical methods: Pleuronema pulchra n. sp. is characterized by a body size of 75-90 × 25-40 µm in vivo, 32-48 somatic kineties, four to seven preoral kineties, somatic kinety 1 composed of about 80 kinetids, and membranelle 2a with a single-rowed mid-portion and hook-like posterior portion. Pleuronema warreni n. sp. is defined by a body size of 55-80 × 25-45 µm in vivo, 35-42 somatic kineties, three to six preoral kineties, somatic kinety 1 with approximately 75 kinetids, mid-portion of membranelle 2a single-rowed and extremely long (occupied > 75% length of M2a). The phylogenic analysis of the small subunit ribosomal RNA genes of Pleuronema members, including those of the two novel species, shows that the genus Pleuronema is a polyphyletic group. Both new species form a cluster with Pleuronema binuleatum KT033424, P. elegans KF840518 and "P. coronatum" JX310014 (identification to be verified). Additionally, we provide an illustrated key for 20 "coronatum-type" Pleuronema species, including the two new ones.