| Abstract: | Four new species of Vorticella, V. parachiangi sp. n., V. scapiformis sp. n., V. sphaeroidalis sp. n., and V. paralima sp. n., were isolated from coastal brackish waters of southern China. Their morphology, infraciliature, and silverline system were investigated based on observations of specimens both in vivo and following silver staining. Vorticella parachiangi sp. n. is distinguished by: a J‐shaped macronucleus; a single dorsally located contractile vacuole; a two‐rowed infundibular polykinetid 3, in which row 1 is shorter than row 2; 21–31 silverlines between peristome and aboral trochal band, 6–11 between aboral trochal band and scopula. Vorticella scapiformis sp. n. is characterized by its conspicuously thin and irregularly edged peristomial lip; a J‐shaped macronucleus; a single, ventrally located contractile vacuole; row 1 of the infundibular polykinetid 3 proximally shortened; 18–25 silverlines between peristome and aboral trochal band, 8–12 between aboral trochal band and scopula. Vorticella sphaeroidalis sp. n. can be identified by its small, sub‐spherical zooid; a C‐shaped macronucleus; a ventrally located contractile vacuole; an aboral trochal band adjacent to the scopula; 16–18 silverlines between persitome and aboral trochal band, two between aboral trochal band and scopula. Vorticella paralima sp. n. can be identified by its ovoidal zooid; a J‐shaped macronucleus; a dorsally positioned contractile vacuole; rows 1 and 2 of the infundibular polykinetid 3 proximally shortened; 26–35 silverlines from peristome to aboral trochal band, and 7–13 from aboral trochal band to scopula. The SSU rDNA genes of these four species were sequenced and their phylogeny was analyzed. |
