New contributions to the marine benthic ciliates from the Antarctic area, including description of seven new species (Protozoa, Ciliophora) Author Wilbert, Norbert Author Song, Weibo text Journal of Natural History 2005 2005-04-30 39 13 935 973 http://dx.doi.org/10.1080/00222930400001509 journal article 10.1080/00222930400001509 1464-5262 4657793 Amphileptus sp. ( Figures 1A , 12A ) We identified this organism from a protargol-impregnated slide ( n 54). Since no living observation was able to be carried out, that is, the morphology in vivo and the position/ Figure 1. (A) Amphileptus sp., (B) Pleuronema coronatum and (C) Philasterides cf. armatalis after protargol impregnation. (A) Right side view of infraciliature, arrows mark the suture formed by some shortened kineties, arrowheads indicate the extrusomes; (B) ventral-left view, to show the general appearance of infraciliature and nuclear apparatus (arrows mark the micronuclei); (C) left side view, arrowhead marks the apical plate; arrow indicates the anterior end of paroral membrane, double-arrowheads mark the scutica. Ma, macronucleus; M13, membranelle 1, 3. Scale bars: 70 M m (A); 30 M m (B); 15 M m (C). number of the contractile vacuoles as well as other diagnostic characters remain unclear, this organism has to be hence treated as an unknown form here. Description Cells after protargol impregnation generally form-constant ( Figure 1A ), ca 200 M m in length, which seems not to have evident (?) tail. Two ellipsoid macronuclear nodules, large and in mid-body position, arranged closely together. No micronucleus detected. Extrusomes (in protargol-impregnated specimens) rod-shaped, slightly curved, about 8–10 M m long; densely distributed in oral region and scattered in other parts of body ( Figures 1A , 15A ). Infraciliature typical of genus. On right side, ca 50 densely ciliated somatic kineties forming a conspicuous suture in mid-body (arrows in Figure 1A ) whereas on left side probably over 12 (? not clearly detected) loosely ciliated kineties (including perioral kinety), all of which seem to extend along whole length of cell. Dorsal brosse composed of ‘‘numerous’’ basal body pairs and extending posteriorly to about half of cell length. Remarks Most studies using modern methods on this genus have been carried out on freshwater forms (Fryd-Versavel et al. 1975; Foissner 1984 , 1986; Dragesco and Dragesco-Kernéis 1986 ; Song and Wilbert 1989 . Considering the cell size, general appearance after impregnation and the habitat, the present organism is similar to the large marine form, Amphileptus marinus ( Kahl 1931 ) which was recently redescribed by Song et al. (2003) . The latter has, however, conspicuously lower number of right somatic kineties (ca 50 versus 20–27). It possibly represents an undescribed form, but further information is required.