Holosticha, Wrzesniowski, 1877

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 : 958-960

Holosticha sp.

( Figure 10A–C )

In view of its body size, the extremely shortened midventral rows with only a few pairs of cirri and the presence of large ‘‘extrusomes’’ (cortical granules?), this small Holosticha possibly represents an unknown form. Unfortunately, only a small number of protargolimpregnated individuals were observed on a permanent slide and no other necessary

information, e.g. features observable in life or biometrical data, is available. Further studies are required in order to determine the identity of this taxon.

Description

Body shape in vivo unknown; after impregnation, broadly oval, about 65640 M m in size; buccal field about two-fifths of cell length ( Figure 10A ). Distal end of adoral zone evenly bent towards right side with ca 17 membranelles, the longest bases of adoral membranelles about 8–10 M m long. Paroral and endoral membranes short and straight, pharyngeal fibres over 20 M m long ( Figure 10A ). About 30 macronuclear nodules distributed throughout the cell, each oval in shape and ca 4 M m long; four globular micronuclei recognizable, which are relatively large (3 M m across). On dorsal side, always several argentophilic extrusome-like structures (cortical granules?), which are about 3 M m in length, vase-shaped with rounded posterior end and positioned along dorsal kineties ( Figure 10B, C ).

Three frontal cirri, only slightly enlarged and difficult to separate from the midventral cirri; one buccal cirrus near anterior end of undulating membranes; two fronto-terminal cirri between distal end of adoral zone of membranelles and anterior end of right marginal row. Midventral rows atypical and very short, consisting of only three to four pairs of cirri, posterior to which there is a single row with three to five cirri extending to about midway along the cell ( Figure 10A ). Six to seven enlarged transverse cirri forming J-shape, immediately anterior to which two small cirri are often observed. Right marginal row consisting of ca 17 cirri, left row with about 14; the two rows are widely separated at posterior cell end.

Four dorsal kineties, each with about 6–15 cilia (cilia about 5 M m long), no caudal cirri ( Figure 10C ).

Figures

Figure 10. (A–C) Holosticha sp. and (D–G) Metaurostylopsis rubra after protargol impregnation. (A) Ventral view, arrows mark the fronto-terminal cirri; (B) detailed portion, to show the extrusomes; (C) dorsal view, arrows mark the extrusomes; (D) ventral view, to show general structure of ciliature; (E, F) cells in middle and late divisional stage, arrows in (F) mark the fronto-terminal cirri, arrowheads indicate transverse cirri; (G) macronuclei. Scale bar: 40 Mm.