title: Morphology and Molecular Phylogeny of Two Poorly Known Species of Protocruzia (Ciliophora: Protocruziida).
abstract: The ciliate genus Protocruzia is a highly confused group, which was formerly placed in the class Heterotrichea or Karyorelictea, and is according to the most recent system tentatively assigned to the class Spirotrichea. In the present study, the morphology, ciliary pattern, and molecular phylogeny of two poorly known species, Protocruzia tuzeti Villeneuve-Brachon, 1940, and Protocruzia granulosa Kahl, 1933, isolated from coastal waters of China, were investigated. Protocruzia tuzeti differs from its congeners mainly in possessing 6 adoral membranelles, 8-11 somatic kineties, and postoral dikinetids. Protocruzia granulosa is characterized by its extremely slender body, three postoral kineties, and 13 or 14 somatic kineties. The morphogenesis of P. granulosa is similar to that of P. tuzeti, especially in the parakinetal mode of stomatogenesis and the reorganization of the parental paroral membrane; however, more than one somatic kinety joins in the formation of the oral primordium in P. granulosa. Phylogenetic analyses based on small subunit ribosomal RNA gene revealed that six Protocruzia species form a fully supported clade that does not belong to any ciliate class; therefore, our data support the establishment of the class Protocruziea Gao et al. (Sci. Rep., 6, 2016, 24874).
authors.affiliation: Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.|College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China.
authors.forename: Jiamei
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
authors.affiliation: Zoology Department, King Saud University, Riyadh, 11451, Saudi Arabia.
authors.forename: Saleh A
authors.initials: SA
authors.lastname: Al-Farraj
authors.affiliation: Laboratory of Protozoology, Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, South China Normal University, Guangzhou, 510631, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Lin
authors.affiliation: Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
authors.forename: Xiaozhong
authors.initials: X
authors.lastname: Hu
mesh_terms: D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D002681:China; D016798:Ciliophora / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000648:ultrastructure*; D016054:DNA, Protozoan / Q000032:analysis / Q000235:genetics; D004275:DNA, Ribosomal / Q000032:analysis / Q000235:genetics; D020459:Genes, rRNA / Q000235:genetics; D009024:Morphogenesis; D015388:Organelles / Q000502:physiology / Q000648:ultrastructure; D010802:Phylogeny; D054679:Ribosome Subunits, Small / Q000235:genetics; D012623:Seawater / Q000469:parasitology; D013045:Species Specificity
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal
keywords: 
  SSU rDNA
  ; Ciliate; morphogenesis; taxonomy