5. Pseudourostyla subtropica Chen, Miao, Ma, AlRasheid, Xu and Lin, 2014

(Fig. 5)

Material examined. Brackish water (salinity 10‰) taken from the River Gyeongpocheon, Unjeong-dong, Gangneung-si, Gangwon-do, Korea (N37°47 ʹ 20 ʺ, E128°54 ʹ 34 ʺ) on February 16, 2017 .

Diagnosis. Body size 295-345 × 90-110 μm in vivo; elliptical body shape; colorless; spherical cortical granules, sparsely distributed, arranged irregularly; about 110 adoral membranelles; single buccal cirrus; about 30 frontal cirri as bicorona; 2 frontoterminal cirri; about 10 transverse cirri; about 18 midventral pairs; about 7 left and 5 right marginal cirral rows; numerous macronuclear nodules; two contractile vacuoles near left side of anterior and posterior parts; brackish habitat.

Distribution. China, Korea (this study).

Remarks. The Korean and type population have slightly different body sizes (295-345 × 90-110 μm vs. 300- 450 × 100-200 μm) (Berger, 2006; Chen et al., 2014). Pseudourostyla subtropica Chen et al., 2014 is closely related to P. cristata (Jerka-Dziadosz, 1964) Borror, 1972, but has different numbers of left marginal rows (7 vs. 4-6) and right marginal rows (5 vs. 4 or 5) (Berger, 2006; Chen et al., 2014).

Voucher slides. Two slides, including protargol-impregnated specimens, were deposited at the National Institute of Biological Resources, Korea (NIBRPR0000107900, NIBRPR0000107901).