Diophrys scutum (Dujardin, 1841) Kahl, 1932

Wilbert, Norbert & Song, Weibo, 2008, A further study on littoral ciliates (Protozoa, Ciliophora) near King George Island, Antarctica, with description of a new genus and seven new species, Journal of Natural History 42 (13 - 14), pp. 979-1012 : 997-999

Diophrys scutum (Dujardin, 1841) Kahl, 1932

( Figure 10D )

Many specimens were found in the protargol-impregnated slides. The Antarctic isolation matches the population report by Song and Packroff (1997) perfectly. Hence, no redescription is necessary.

This well-known form is characterized by the large size (usually.140 Mm in length), high number of densely-ciliated dorsal kineties (6–9), strongly curved distal end of adoral zone, elongated macronuclear nodules and numerous membranelles (over 60). However, many ‘‘abnormal’’ forms have been observed, of which the ciliature is highly changeable, especially regarding the number of frontoventral cirri.

Euplotes balteatus (Dujardin, 1841) Kahl, 1932

( Figures 13A–D ; Table 4)

This form was recently redefined by Song and Wilbert (2002a) on the basis of an Antarctic population. The current sample is identical to that, and therefore only some extra points will be mentioned here.

Description

Body broadly oval, size about 48–61×40–52 Mm after protargol impregnation. Buccal field ca. 2/3–3/4 of cell length; proximal end of adoral zone often sharply curved ( Figure 13A ). About 30 adoral membranelles, consistently 10 strong frontoventral, five transverse, two left marginal and two caudal cirri, the two marginal ones being situated separate from one another and often posterior to the level of transverse cirri ( Figure 13C , arrowheads). Always 9–10 dorsolateral kineties in the present populations, comprising about 8–10 kinetosomes in the mid-dorsal rows ( Figure 13D ).

Remarks

Three small and morphologically similar Euplotes have been found in the same biotopes in the current survey (see below), and the diagnostic features are listed in Table 4. This form should be identified by the number of dorsolateral kineties, the silverline system (see Song and Wilbert 2002), comparatively strong cirri, two clearly separated marginal cirri, the small size and the general appearance of the adoral zone (large, about 90 ° bent in the posterior portion etc.) ( Song and Wilbert 2002a).

Figures

Figure 10. Condylostoma spatiosum (A, B), Diophrys scutum (D), Diophrys aff. oligothrix (C, G), Diophrys appendiculata (E), Euplotes vannus (F) and Euplotes dragescoi nov. spec. (H–K) after protargol impregnation. (A) Dorsal view, to show the general appearance, arrow marks the beaded macronucleus. (B) Caudal portion, arrowhead marks the suture. (C) Dorsal view, to show the dorsal kineties (arrows). (D) Ventral view, to show the general infraciliature. (E) Ventral view, arrow marks the pre-transverse cirrus, double-arrowheads indicate the transverse cirri, while arrowhead points to the anterior marginal cirrus. (F) Dorsal view, arrowheads mark the three caudal cirri, arrow indicates the macronucleus. (G) Ventral view, arrow marks the pre-transverse cirrus. (H) Detail of a divider, arrowheads mark the newlyformed two marginal cirri (note the different sizes). (I) Dorsal view, to show the ridges. (J) Ventral view, arrow marks the anterior (large) marginal cirrus, double-arrowheads indicate the paroral membrane. (K) Detail of ventral view, arrow and arrowhead indicate the small and large marginal cirrus, respectively. Scale bars: 200 Mm (A); 100 Mm (D); 50 Mm (E–G, J).

Figure 13. Euplotes balteatus (A–D), Euplotes petzi nov. spec. (E–H) and Euplotes rariseta (I– N) after protargol impregnation. (A–C) Ventral view of three specimens, to show the general appearance of infraciliature, arrow in A marks the strong and loosely arranged transverse cirri, arrowheads in C indicate the two marginal cirri. (D) Dorsal view, note that the basal bodies are loosely arranged. (E, G, H) Ventral view, note the two small and closely- spaced marginal cirri (arrow and arrowheads). (F) Dorsal view. (I, K) Ventral view, arrows mark the single marginal cirrus, arrowheads in K indicate the weak and close-set transverse cirri. (L) Ventral view, arrowhead marks the two anteriormost frontoventral cirri. (M) Ventral view, to show the adoral zone and the marginal cirrus (arrowhead). (N) Ventral view, arrow indicates the paroral membrane. Scale bars: 20 Mm (A, I); 35 Mm (E).