Thigmokeronopsis stoecki

Chen, Xumiao, Li, Liqiong, Hu, Xiaozhong, Shao, Chen, Al-Farraj, Saleh A. & Al-Rasheid, Khaled A. S., 2013, A Morphogenetic Description of Thigmokeronopsis stoecki Shao et al., 2008 (Ciliophora, Hypotricha) and a Comparison with Members of the Family Pseudokeronopsidae, Acta Protozoologica 52 (2), pp. 65-72 : 66

Morphology of Thigmokeronopsis stoecki based on present population ( Figs 1–7 , Table 1)

Body size in vivo about 140–230 × 70–80 µm; cell highly contractile and shape variable, generally elongated fusiform with anterior slightly narrow and round- ed, and posterior tapered ( Figs 1, 4, 5 ). Cell brownish to dark brown in color. Adoral zone about 40% of cell length. Pellicle flexible and thin, with brightly grassgreen cortical granules (about 2 µm long, red blood cell-shaped) sparsely distributed beneath ( Figs 6, 7 ). Cytoplasm colorless, filled with many tiny lipid droplets. More than 100 macronuclear nodules. Contractile vacuole positioned in anterior two-fifths on left side of cell.

Adoral zone composed of 70–83 membranelles, with its distal end curving strongly posteriad along the right cell margin and extending to about cytostome level. Fifteen to 26 frontal cirri, which are not clearly distinguished from the midventral cirri posteriorly, forming typical curved bicorona. Two frontoterminal, one buccal and five to eight transverse cirri. Midventral complex comprising a total of 32–40 pairs of cirri that are distinctly separated and thus are not arranged in a typical zig-zag pattern, terminating near the transverse cirri. Left and right marginal row with 46–65 and 47–55 cirri respectively, nearly confluent posteriorly. Thigmotactic field (TF) dominant, consisting of 11–15 densely arranged, longitudinal rows of cirri. Three complete dorsal kineties ( Figs 2, 3 ).

Figures

Figs 1–7. Morphology and photomicrographs of Thigmokeronopsis stoecki from life (1, 4–7) and after protargol impregnation (2, 3). 1 – ventral view of a representative individual (from Shao et al. 2008b); 2, 3 – ventral and dorsal views of the infraciliature (from Shao et al. 2008b); 4 – ventral view of a typical individual; 5 – dorsal view, to show the distinct flexibility of the body; 6 – dorsal view of anterior portion, to show the transparent cytoplasm and sparsely distributed cortical granules (arrows); 7 – dorsal view, noting the arrangement of cortical granules (arrows). AZM – adoral zone of membranelles, DK – dorsal kineties, FC – frontal cirri, LMR – left marginal row, Ma – macronuclear nodules, MC – midventral complex, RMR – right marginal row, TC – transverse cirri, TF – thigmotactic field. Scale bars: 100 µm (in Figs 1, 4, 5) and 50 µm (in Figs 2, 3).