Condylostoma cf. magnum Spiegel, 1926

Wilbert, Norbert & Song, Weibo, 2005, New contributions to the marine benthic ciliates from the Antarctic area, including description of seven new species (Protozoa, Ciliophora), Journal of Natural History 39 (13), pp. 935-973 : 950-951

Condylostoma cf. magnum Spiegel, 1926

( Figure 7A–C )

This organism was only found from protargol-impregnated slides and no in vivo data (e.g. concerning the body shape and size) are available. With reference to the infraciliature, it is extremely similar to the well-known species, Condylostoma magnum Spiegel, 1926 , but differs from the latter, however, in having fewer somatic kineties (ca 30 versus 47–56) (Dragesco 1996; Song and Wilbert 1997), which indicates that these two forms might not be conspecific. As a document contribution to studies in the future, a brief description is supplied here.

Description

Cells about 250 M m long after impregnation, no tail present although caudal end might be conspicuously pointed ( Figure 7A ). Buccal field probably relatively small (about one-sixth of body length after fixation) ( Figure 7C ). Macronucleus moniliform with ca 10 ellipsoid nodules, lying slightly to right of main body axis ( Figure 7B ).

Somatic kineties composed of paired basal bodies as in other congeners, both ciliated with relatively short cilia. About 30 somatic kineties, some of which terminate subcaudally.

Adoral zone of membranelles conspicuous, consisting of more than 120 membranelles with proximal portion extending spirally into dominant buccal cavity. Paroral membrane developed, on right of dominant buccal cavity, terminating posteriorly near cytopharynx ( Figure 7C ). The number of cirri-like membranelles at distal end of adoral zone (at least two) not exactly determined because of the invagination and contraction of related portion ( Figure 7C , arrowhead).

Figures

Figure 7. (A–C) Condylostoma cf. magnum and (D–H) Heterostentor coeruleus from life (D–F) and after protargol impregnation (A–C, G–H). (A) Ventral view, arrows mark the shortened kineties; (B) dorsal view, arrows mark the macronuclear nodules; (C) anterior portion of ventral view, arrow marks the paroral membrane, arrowhead and double-arrowheads point to the distal and proximal ends of adoral zone of membranelles, respectively; (D) a slightly contracted individual; (E) anterior portion, to show the appearance of the membranelles; (F) diagram of movement while attached to the bottom, arrow indicates the caudal region used as attachment area; (G, H) details of pellicle, arrows mark the pigments (cortical granules). Scale bars: 100 Mm (A, B); 30 Mm (C); 80 Mm (D).