Abstract
Two marine hypotrichous ciliates, Metaurostylopsis sinica nov. spec. and M. salina Lei et al. 2005, isolated from the northern china sea are studied using live observation and protargol impregnation. The new species is characterized by its slender, yellow-brownish body with two types of cortical granules. It has four frontal, two frontoterminal, one buccal and five to eight transverse cirri, 11-15 midventral cirral pairs. three left and two right marginal cirral rows and three complete dorsal kinetics. The main morphogenetic features are: (1) no ventral cirral row posterior to the midventral rows is formed, and (2) the macronuclear nodules fuse into a single mass as in most urostylids. Based on the Qingdao population, additional observations for M. salina Lei et al. 2005 are documented and a redescription is provided. The small subunit rRNA genes of M. sinica and M. salina were sequenced in order to compare their similarities.