Pseudochilodonopsis marina Song, 1991

Choi, Jung Min, Jung, Jae-Ho & Kim, Jung-Hoon Kang and Young-Ok, 2020, New record of four ciliates (Protozoa, Ciliophora) collected from rocky intertidal pools of South Korea, Journal of Species Research 9 (4), pp. 455-461 : 458-459

3. Pseudochilodonopsis marina Song, 1991 ( Fig. 4 )

Material examined. Marine water (temperature 14.5°C; salinity 32.5; pH 8.5) collected from Oryukdo , Yongho-dong, Nam-gu, Busan, South Korea (35°05′58″N 129° 07′25″E) on April 22, 2012 ( Fig. 1 ; St. 2) .

Diagnosis. Body size 40-60 × 28-35 μm, length: width ratio about 1.4: 1 in vivo; 41-65 × 21-38 μm after protargol impregnation; outline reniform; dorsoventrally flattened about 2: 1; single macronucleus 13-18 × 9-17 μm in size; 2 contractile vacuoles obliquely located; 10-15 nematodesmal rods; 7 left and 5 right kineties on ventral side; 5 fragmented preoral kineties; terminal fragment positioned apically on dorsal side, consisting of 5-7 basal bodies.

Distribution. China and Korea.

Remarks. The Korean population of P. marina highly resembles the original description by Song (1991) but, slightly differs in the size of macronucleus (ca. 15.5 × 11.9 vs. ca. 19.5× 13.3) ( Song, 1991; Liu et al., 2008).

The closest congener P. similis Song & Wilbert, 1989 differs from the Korean population as follows: location of terminal fragment (apical vs. subapical); basal body number of the terminal fragment (5-7 vs. 8-10); number of nematodesmal rods (10-15 vs. 16-18) ( Song and Wilbert, 1989).

Voucher slides. Two slides with protargol-impregnated specimens was deposited at National Institute of Biological Resources (NIBRPR0000110831) and Korea Institute of Ocean Science and Technology (KIOST), respectively.

Figures

Fig. 4. Photomicrographs of Pseudochilodonopsis marina from living specimens (A-C) and protargol impregnated specimens (D, E). A. Ventral view of typical individual. B. Two contractile vacuoles (arrowheads). C. Lateral view. D, E. Ventral and dorsal view of stained specimens. Cs, cytostome; LSK, left somatic kineties; Ma, macronucleus; Pr, preoral kineties; RSK, right somatic kineties. TF, terminal fragment. Scale bars: 30μm.

Fig. 1. Map of the sampling stations in South Korea. Each station (marked with red circles) located at three intertidal zones of the Korean Peninsula (St. 1-3) and Baekdo Island (St. 4).