Dexiotrichides pangi n. sp. (protozoa, ciliophora, scuticociliatia), a new marine ciliate from the north China sea.

The morphology, infraciliature, and silverline system of a new marine scuticociliate, Dexiotrichides pangi n. sp. were investigated. The new species is characterized by: size about 45-65 x 20-25 microm in vivo with kidney-like body shape and obliquely truncated semicircle-shaped apical plate; cytostome at bottom of conspicuously depressed oral cavity, which is located at the cell equatorial level; paroral membrane extending anteriorly to membranelle 3; scutica multi-rowed; 33-38 somatic kineties; contractile vacuole near ventral side and subcaudally positioned, opening at posterior end of somatic kinety 3; one oval macronucleus and one small micronucleus; caudal cilium positioned in a small pouch; marine habitat. Based on the data obtained, an improved diagnosis for the genus Dexiotrichides is suggested: body with circular cross-section and conspicuous cilia-free apical plate; buccal cavity conspicuously depressed with cytostome located near or at equatorial level; three membranelles transversely orientated each with 2-3 rows; paroral membrane zigzaging structure, extending to about half of the length of buccal field; multi-rowed scutica; somatic kinety one strongly shortened and terminating anteriorly at posterior end of buccal field; basal bodies in equatorial region arranged usually in circular pattern, while in the anterior portion of somatic kinety 2, basal bodies characteristically in pairs and separated from the posterior part of kinety 2; one caudal cilium.