Morphology of three new colonial sessile peritrich ciliates, Pseudepistylis paramphora n. sp., Zoothamnium paranii n. sp. and Z. hartwigi n. sp., with notes on Epicarchesium variabile (Ciliophora, Peritrichia)

Four colonial sessile peritrichs were discovered during a survey of ciliate diversity of coastal waters of the Yellow Sea, Shandong Province, China. Following studies of their living morphology, infraciliature and silverline system, three were identified as new members of the genera Pseudepistylis and Zoothamnium. Pseudepistylis paramphora n. sp. is the second species assigned to the genus, which is characterized by its rigid, dichotomously branched stalk, reticulate silverline system and marine habitat. Zoothamnium paranii n. sp. was isolated from brackish water and Z. hartwigi n. sp. was collected from marine water. Zoothamnium paranii is characterized largely by its highly variable zooid size and having an extremely long infundibular polykinety 3. Zoothamnium hartwigi is separated from its congeners by having two types both of peristomial lip and infundibular polykinety 3. We also supply supplementary morphometric data and photomicrographs of Epicarchesium variabile based on examinations of specimens in vivo and after silver staining.