Pleuronema coronatum Kent, 1881

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 : 947

Pleuronema coronatum Kent, 1881

( Figures 1B , 13H, M )

This species was also identified from protargol-impregnated specimens (with numerous individuals). All morphometrical data correspond to the previous descriptions perfectly ( Dragesco 1968; Song and Wilbert 2002). Hence only some extra data will be supplied here.

Micronuclei almost always several in number and closely adjacent to the rounded, large macronucleus. The Antarctic population has on average 40 somatic kineties, of which about five are shortened posteriorly on the left of the buccal field ( Figure 1B ).

Figures

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 Mm (A); 30 Mm (B); 15 Mm (C).

Figure 13. Photomicrographs of (A–G) Pithites pelagicus nov. spec., (H, M) Pleuronema coronatum and (I–L) Intranstylum antarcticum nov. spec. after protargol impregnation. (A) Lateral view of the anterior portion; arrows mark the cytopharynx; (B) dorsal side view (looking from ventral to dorsal) of anterior portion, arrow indicates the terminal fragment (‘‘dorsal brush’’); (C) ventral view, arrows mark the gap between left and right somatic kineties; (D) ventral view, to show the contractile vacuole pore (arrow); (E) ventral view of apical area, arrows mark the fragment-like perioral kineties; (F) ventral view of a specimen in division; (G) ventral view at a later stage of division, white arrows mark the newly formed oral apparatus in the opisthe, while the black arrow indicates the contractile vacuole pore; (H) left-lateral view, the arrowheads point to the posterior end of paroral membrane, the black arrow indicates whereas the macronucleus; (I, L) stalk, arrowheads in (I) mark the attached diatoms (?); (J) two zooids, arrows indicate the reduced spasmoneme; (K) to show the spasmoneme (arrow); (M) left-lateral view, arrowhead marks the micronucleus, arrows point to the membranelle 3.