AUTHOR=Liu Mingjian , Wang Chundi , Hu Xiaozhong , Qu Zhishuai , Jiang Limin , Al-Farraj Saleh A. , El-Serehy Hamed A. , Warren Alan , Song Weibo 

TITLE=Taxonomy and Molecular Phylogeny of Three Species of Scuticociliates From China: Citrithrix smalli gen. nov., sp. nov., Homalogastra binucleata sp. nov. and Uronema orientalis Pan et al., 2015 (Protozoa, Ciliophora, Oligohymenophorea), With the Proposal of a New Family, Citrithrixidae fam. nov.

JOURNAL=Frontiers in Marine Science

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2020.604704

DOI=10.3389/fmars.2020.604704

ISSN=2296-7745

ABSTRACT=<p>The morphology and taxonomy of three scuticociliates found in China, viz. <italic>Citrithrix smalli</italic> sp. nov., <italic>Homalogastra binucleata</italic> sp. nov., and <italic>Uronema orientalis</italic> Pan et al., 2015, were investigated. The small subunit ribosomal RNA (SSU rRNA) gene of these species, and the cytochrome <italic>c</italic> oxidase subunit I (<italic>COI</italic>) gene of <italic>Uronema orientalis</italic>, were sequenced and compared with those of related taxa to determine their systematic positions. The new monotypic genus <italic>Citrithrix</italic> gen. nov. is characterized by its lemon-shaped body, posteriorly located cytostome, dominant oral groove, and the compact structure of its multi-rowed membranelles 1 and 2 (M1, M2). Based on both morphological and molecular data, this new genus cannot be assigned to any known family and thus, a new family, Citrithrixidae fam. nov., is proposed within the order Philasterida. <italic>Homalogastra binucleata</italic> sp. nov., a brackish water form (salinity 2‰), differs from all congeners in having two macronuclear nodules. <italic>Uronema orientalis</italic> closely resembles the type population in all respects other than having fewer somatic kineties.</p><p>This article is registered in ZooBank under: urn:lsid:zoobank.org:pub:5727F18E-5421-446D-B22C-774783539FE4.</p>