Aspidisca orthopogon Deroux & Tuffrau, 1965

Kim, Ji Hye, Omar, Atef & Jung, Ji Hye Moon and Jae-Ho, 2020, Taxonomy of 16 indigenous ciliate species (Protozoa, Ciliophora) from South Korea, Journal of Species Research 9 (4), pp. 427-442 : 429

2. Aspidisca orthopogon Deroux & Tuffrau, 1965

( Fig. 2 )

Material examined. Marine water with some debris (salinity, 29.3‰) collected from Hamdeok Beach , Jocheoneup, Jeju-si, Jeju-do, Korea (33°32′36″N 126°39′51″E) on 8 Jun 2019 .

Diagnosis. Body size in vivo 95-105 × 55-65 μm (n =3); broad elliptical; 1 small and 7 distinct frontoventral cirri with polystyla -arrangement; single contractile vacuole located subterminally; 5 transverse cirri; 4 dorsal kineties; adoral zone of membranelles (AZM) bipartite, AZM1 composed of 4 membranelles; AZM2 composed of 41-45 membranelles, posterior thorn-like projection absent.

Distribution. China, Korea (Type locality is not mentioned).

Remarks. The Korean population of Aspidisca orthopogon corresponds very well to the Chinese population ( Li et al., 2008). They only differ in the absence (vs. presence) of the thorn-like projection in the rear body end. Aspidisca orthopogon is also similar to A. magna in the body size (95-105× 55-65 μm vs. 50-100× 40-80 μm), but can be easily distinguished from this species and other congeners by the enormous posterior adoral zone (AZM2), which is composed of 41-45 membranelles (vs. 12-13 in A. aculeata , 15-18 in A. magna , and 14-21 in A. leptapsis ) ( Li et al., 2008; 2010).

Voucher slides. Two slides with protargol-impregnated specimens were deposited at the National Institute of Biological Resources (NIBRPR0000110192, NIBRPR0000 110193).

Figures

Fig. 2. Photomicrograph of Aspidisca orthopogon in vivo (A, B) and after protargol impregnation (C, D). A, B. Body shape in vivo (arrow indicates contractile vacuole in B). C. Ventral ciliature (arrow marks small frontoventral cirrus). D. Dorsal kineties. AZM1-2, adoral zone of membranelles 1 and 2; DK, dorsal kinety; TC, transverse cirrus. Scale bars=50 μm(A, B); 30 μm (C).