During faunistic studies of ciliates in coastal waters of Daya Bay and Bohai Bay, China, two previously unknown ciliates were discovered and investigated using standard taxonomic methods. Morphological comparative analyses revealed that they represent two novel species in the genusChaenea. Chaenea paucistriata spec. nov. can be distinguished from its congeners by the following traits: body length in vivo about 180–250 µm; eight somatic kineties; dorsal brush rows 1–4 consisting of three, five, seven, and two dikinetids, respectively; rod-like extrusomes, 8 µm long; 63–94 macronuclei; cortical granules minute and colourless. Chaenea sinica spec. nov. differs from its congeners in having: body length in vivo about 140–240 µm; 17–21 somatic kineties; dorsal brush rows 1–4 consisting of 3–7, 10 or 11, 11–13, and 3–6 dikinetids, respectively; rod-like extrusomes about 6–8 µm long; 71–164 macronuclei. A key is presented to assist the identification of allChaenea species.

Two oxytrichid freshwater ciliates, Apoamphisiella tihanyiensis (Gellért and Tamás, 1958) Foissner, 1997 and Notohymena australis (Foissner and O’Donoghue, 1990) Berger, 1999, were recorded for the first time in Lake Biwa, a 4-million-year-old lake located at the Shiga Prefecture in Japan. Their morphology was investigated based on observations of live and protargol-impregnated material. Based on the present observation and previous descriptions, A. tihanyiensis is characterized by having an elliptical body shape, yellowish cortical granules, two long frontoventral rows, enlarged frontal and transverse cirri, highly variable numbers of frontoventral, and postoral ventral cirri, and six to 11 caudal cirri arranged in three short rows. New data confirm the presence of pretransverse ventral cirri in this species. Morphologically, N. australis differs from its congeners in having the following combination of characters: greenish cortical granules, the cirrus V/2 located slight anterior to the leftmost transverse cirrus, dorsal kinety 3 almost as long as body, and seven to 10 caudal cirri arranged in three short rows. Morphogenesis in N. australis shows the same pattern as in N. apoaustralis but differs from that of other congeners in the origin of oral primordium and the formation of more than just three caudal cirri.

We isolated a relatively unknown haptorian ciliate, Trachelophyllum brachypharynx, in brackish water from the mouth of the Taehwa River, South Korea. The morphology of this isolate was studied using in vivo observation and protargol impregnation, and its evolutionary history was revealed by phylogenetic analysis of the 18S rRNA gene. The main features of T. brachypharynx include (i) a very narrowly fusiform and slightly contractile body about 380 × 40 μm in size; (ii) two ellipsoidal macronuclear nodules typically connected by a fine strand; (iii) a single terminal contractile vacuole; (iv) filiform extrusomes that are typically 30 µm long; (v) an average of 24 ciliary rows, with two of them anteriorly differentiated into an isostichad dikinetidal dorsal brush; and (vi) hat-shaped lepidosomes. Based on the 18S rRNA gene phylogeny, T. brachypharynx clustered together withTrachelophyllum sp. within the order Spathidiida. Furthermore, phylogenetic trees and networks indicate some members from the genera Enchelyodon and Spathidium as the nearest relatives of trachelophyllids. Therefore, based on the present molecular and comparative-morphological analyses, we suggested a hypothesis explaining how trachelophyllids may have evolved from a spathidiid-like ancestor via an enchelyodonid-like stage.