Morphology and morphogenesis of Apoholosticha sinica n. g., n. sp. (Ciliophora, Hypotrichia), with consideration of its systematic position among urostylids

• Published in: European journal of protistology Vol. 50; no. 1; pp. 78 - 88
• Main Authors: Fan, Yangbo, Chen, Xumiao, Hu, Xiaozhong, Shao, Chen, Al-Rasheid, Khaled A.S., Al-Farraj, Saleh A., Lin, Xiaofeng
• Format: Journal Article
• Language: English
• Published: Munich Elsevier GmbH 01.02.2014; Elsevier
• Subjects: Apoholosticha sinica n. g., n. sp; Biological and medical sciences; China; Ciliophora; DNA, Protozoan - genetics; DNA, Ribosomal - genetics; Fundamental and applied biological sciences. Psychology; Hypotrichida - classification; Hypotrichida - cytology; Hypotrichida - genetics; Hypotrichida - growth & development; Marine ciliates; Molecular Sequence Data; Morphogenesis; Morphogenesis - physiology; Phylogeny; Protozoa; Species Specificity; SSU rDNA; Systematics. Geographical distribution. Morphology. Cytology; Taxonomy; Urostylida; Asia; China; ISEW, China, People's Rep., Guangdong Prov., Shenzhen; China, People's Rep; Morphogenesis; Apoholosticha sinica n. g., n. sp; SSU rDNA; Phylogeny; Taxonomy; Marine ciliates; Brackish water environment; Protozoa; New genus; Ciliophora; Ribosomal DNA; Diagnosis (taxonomy); Mangrove; Morphology; New species
• ISSN: 0932-4739; 1618-0429
• DOI: 10.1016/j.ejop.2013.06.003

This paper investigates the morphology, morphogenesis and SSU rRNA gene-based phylogeny of Apoholosticha sinica n. g., n. sp., isolated from mangrove wetland in Shenzhen, southern China. The new genus Apoholosticha is characterized by its bipartite adoral zone, clearly differentiated frontal cirri arranged in a bicorona, midventral complex composed of midventral pairs only, one marginal cirral row on each side, presence of frontoterminal and transverse cirri, and the lack of a buccal cirrus and caudal cirri. The type species, Apoholosticha sinica n. sp. is diagnosed by the elongated body shape and two kinds of cortical granules. Its main morphogenetic features are similar to that of Pseudokeronopsis except for (1) no buccal cirrus is formed and (2) its macronuclear nodules fuse into a single mass during cell division. Phylogenetic analyses for the new taxon indicate that Apoholosticha n. g. is most closely related to Nothoholosticha and Heterokeronopsis, and falls into the family Pseudokeronopsidae within the core Urostylida clade. In addition, a species that had been misidentified in previous literature is here recognized and assigned to the new genus as Apoholosticha sepetibensis (Wanick and Silva-Neto, 2004) n. comb. (basionym: Pseudokeronopsis sepetibensis Wanick and Silva-Neto, 2004).