title: Cell division and morphology of the marine ciliate, Condylostoma spatiosum Ozaki and Yagiu (Ciliophora, Heterotrichida) based on a Chinese population.
abstract: The morphology and morphogenesis of the large marine heterotrichous ciliate, Condylostoma spatiosum Ozaki & Yagiu in Yagiu, 1944, isolated from Jiaozhou Bay off Qingdao (Tsingtao), China, were investigated using live observation and protargol impregnation. A detailed redescription is given since no infraciliature data about this "well-studied" species are available. It is characterized by: size in vivo 400-700 x 90-140 microm; buccal field about 1/3 of body length; adoral zone composed of 130 membranelles on average; invariably two prominent membrane-like frontal cirri, which are parallel to each other; about 58 somatic kineties; macronucleus composed of 13-22 fragments. Morphogenesis proceeds basically as described in a previous report and can be summarized as follows: (1) the parental adoral zone of membranelles is partly dedifferentiated and then renewed in the posterior portion; (2) in the proter, both the frontal cirri and the paroral membrane are newly formed by anlagen derived from the disaggregated old structures; (3) in the opisthe the anlagen of the paroral membrane and the frontal cirri develop from the right margin of the oral primordium; (4) two frontal cirri are formed one after the other by the frontal cirral anlage; (5) during morphogenesis, no recognizable duplication of basal bodies takes place in somatic kineties; and (6) the macronucleus divides after prior fusion. One reorganizer was observed showing that the basic process of reorganization is obviously similar to that in division.
authors.affiliation: Laboratory of Protozoology, KLM, Ocean University of China, Qingdao, PR China.
authors.forename: Chen
authors.initials: C
authors.lastname: Shao
authors.forename: Weibo
authors.initials: W
authors.lastname: Song
authors.forename: Xiaozhong
authors.initials: X
authors.lastname: Hu
authors.forename: Honggang
authors.initials: H
authors.lastname: Ma
authors.forename: Mingzhuang
authors.initials: M
authors.lastname: Zhu
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
mesh_terms: D000818:Animals; D002455:Cell Division; D002681:China; D016798:Ciliophora / Q000166:cytology / Q000302:isolation & purification / Q000502:physiology* / Q000648:ultrastructure*; D009024:Morphogenesis; D012038:Regeneration; D012623:Seawater / Q000469:parasitology; D013045:Species Specificity