Euplotes shini Lian et al., 2020

4. Euplotes shini Lian et al., 2020

Material examined. Marine water (salinity 29‰) collected from Buk-myeon, Uljin-gun, Gyeongsangbuk-do, Korea

(37°32 ʹ 5 ʺ N, 130°51 ʹ 21 ʺ E) on May 23, 2023.

Diagnosis. Body size 43.8-55.0 × 20.7-29.1 μm after protargol impregnation (n = 11). Body shape broadly oval; macronucleus C-shaped, with a single small spherical micronucleus attached to it; 45-48 adoral membranelles; 10 frontoventral, 5 transverse, 2 caudal and 1 or 2 marginal cirri ( Fig. 4A View Fig ). 8 or 9 dorsal kineties with 11 or 12 dikinetids in the middle one; dorsal argyrome pattern of single- vannus type ( Fig. 4B, C View Fig ).

Distribution. China ( Lian, 2020) and Korea (present study).

Remarks. The Korean population corresponds well with the Chinese type population described by Lian et al. (2020) in several aspects: buccal field length (72% vs. 75% on average); number of adoral membranelles (45-48 vs. 37- 46), frontoventral cirri (10 vs. 10), caudal cirri (2 vs. 2 or 3), marginal cirri (1 or 2 vs. 2), dorsal kineties (8 or 9 vs. 9), dikinetids in the mid-dorsal row (11 or 12 vs. 10-14); dorsal argyrome pattern (single- vannus), and habitat (marine). Compared to other species in the genus, Euplotes minuta Yocum, 1930 resembles E. shini , but the two species can be differentiated by the size of their marginal cirri, i.e., E. minuta has marginal cirri of approximately the same size ( Park et al., 2010), whereas E. shini has marginal cirri of different sizes. As noted by Lian et al. (2020), E. minuta is presumed to represent a species complex.

Voucher slides. Two slides with protargol-impregnated specimens (MABIK PR00045070, MABIK PR00045071) and one slide with silver nitrate-impregnated specimens (MABIK PR00045069) were deposited at the National Marine Biodiversity Institute of Korea.