Taxonomic Characterization of Three Marine Peritrichous Ciliates from China: Zoothamnium alrasheidi spec. nov., Z. marinum Kahl, 1933 and Z. vermicola Precht, 1935 (Ciliophora: Peritrichia)

Three marine peritrichous ciliates, Zoothamnium alrasheidi spec. nov., Z. marinum Kahl, 1933 and Z. vermicola Precht, 1935, were isolated from littoral areas near Qingdao, China. The living morphology, infraciliature and silverline system were studied in living and silver-impregnated specimens. Zoothamnium alrasheidi is distinguished from its congeners by the giant, leaf-shaped colony, the differentiation of zooids, the structure of the infundibular polykineties and in having 57–75 silverlines between the oral area and the trochal band and 24–42 between the trochal band and the scopula. Zoothamnium marinum and Z. vermicola are reported for the first time in over 70 years. Each was identified by its zooid shape and size, colony shape, the branching pattern of its stalk and its marine habitat. As a result of the present study, additional features for characterizing these species now include the structure of infundibular polykinety 3 and the number of silverlines between the aboral trochal band and (a) the scopula, and (b) the peristomial lip. Redescriptions and improved diagnoses of both species are supplied based on the Chinese populations.