Abstract
Two poorly known marine suctorian ciliates, Ephelota truncata Fraipont, 1878 and Ephelota mammillata Dons, 1918, collected from the coastal waters off Qingdao, China, were investigated using both live observations and protargol impregation methods. Improved diagnoses for both species are supplied based on previous and current studies. The adult form of each species has two types of tentacle, a long stalk and a ramose macronucleus. In addition, E. truncata has a short column-shaped body about 75-250 x 100-200 mu m in vivo, 12-16 suctorial tentacles, 80-100 prehensile tentacles and a stalk that is 500-1200 mu m long; the swanner is ovoid, about 40 x 30 mu m in vivo, with 19-24 somatic kinetics and a C-shaped macronucleus. E. mammillata has a bowl-shaped body about 55-150 x 80-150 mu m in vivo, ca. 10 suctorial tentacles, 30-50 prehensile tentacles and a stalk that is 350-800 mu m long. The SSU rRNA genes were sequenced for both species in order to compare them with those of closely related congeners.