Neokeronopsis asiatica Foissner et al., 2010

Choi, Ji Hye & Jung, Atef Omar and Jae-Ho, 2025, New record of four spirotrichs (Protozoa, Ciliophora) from South Korea, Journal of Species Research 14 (1), pp. 38-47 : 43-44

3. Neokeronopsis asiatica Foissner et al., 2010 ( Fig. 4 )

Material examined. Freshwater (salinity 0.1‰, temperature 6.1℃) collected from Namdaechoen , Seong- nea-dong, Gangnueng-si, Gangwon-do, South Korea (37°44 ʹ 46 ʺ N, 128°52 ʹ 52 ʺ E) on March 11, 2024 .

Diagnosis. Size 222-267 × 110-144 μm after protargol impregnation (n = 3); body elliptical with indentation at site of caudal cirri and slightly flexible; yellowish un- der low magnification; adoral zone occupies about 40% of body length in staining specimens and composed of 81-86 membranelles ( Fig. 4A ), bases of longest membranelles about 16-17 μm long; bicorona consists of 18- 28 frontal cirri, 10-14 cirri in anterior corona and 8-14 cirri in posterior corona ( Fig. 4A ); buccal cirrus lacking; 2-3 frontoterminal, and 15-17 transverse cirri; 12-15 midventral pairs; one left (43-48 cirri) and one right (38-49) marginal cirral rows ( Fig. 4A ); three caudal cirral rows consist of 9-14 cirri; 11-12 dorsal kineties ( Fig. 4B ); two circular to ellipsoidal macronuclear nodules, each 29-39 × 17-21 μm after protargol impregnation; 1-3 globular micronuclei, about 7 μm in diameter after protargol impregnation ( Fig. 4A ).

Distribution. Antarctica ( Jung et al., 2015) , China (type locality, Foissner et al., 2010), Korea (in this study).

Remarks. In the genus Neokeronopsis , two species have been recorded, N. asiatica and N. spectabilis ( Kahl, 1932) Warren et al., 2002 ( Warren et al., 2002; Foissner et al., 2010). The Korean population of Neokeronopsis asiatica corresponds to the type population described by Foissner et al. (2010) and the Antarctica population described by Jung et al. (2015) in all available aspects. However, unfortunately, since we were unable to observe enough materials in vivo for the Korean population, some features cannot be compared with those of the Antarctic population described by Jung et al. (2015). Neokeronopsis asiatica differs from N. spectabilis by the body size (222-267 × 110-144 μm vs. 360-500 × 150-200 μm after protargol impregnation), the shape of posterior body end (indentation at the site of caudal cirri vs. broadly round- ed without indentation), the bases of the longest adoral membranelles (16-17 μm vs. 22-35 μm), and the number of caudal cirri (9-14 vs. 6-9) ( Warren et al., 2002; Berger, 2006; Foissner, 2010).

Voucher slides. Two slides with protargol-impregnat- ed specimens were deposited at the National Institute of Biological Resources (NIBRPR0000111275, NIBRPR 0000111276).

Figures

Fig. 4. Neokeronopsis asiatica after protargol impregnation (A, B). A. Ventral view showing the adoral zone of membranelles, frontal, frontoterminal, caudal, and transverse cirri, and left and right marginal rows. Arrowheads denote micronuclei. B. Dorsal view showing dorsal kineties. AZM, adoral zone of membranelles; CC, caudal cirri; DK, dorsal kineties; FC, frontal cirri; FTC, frontoterminal cirri; LMR, left marginal row; MA, macronuclear nodules; MP, midventral pairs; RMR, right marginal row; TC, transverse cirri. Scale bar: 50μm.