Pseudokeronopsis parasongi Li and Xu, 2020

Omar, Atef & Jung, Ji Hye Choi and Jae-Ho, 2023, New record of ten ciliate species (Protozoa, Ciliophora) from South Korea, Journal of Species Research 12 (1), pp. 95-108 : 96-98

3. Pseudokeronopsis parasongi Li and Xu, 2020

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Material examined. Marine water (salinity 34.5 - 35‰) collected from Gangmun Bridge , Gangmun-dong , Gangneung-si, Gangwon-do, Korea (37°47 ʹ 20 ʺ N, 128°54 ʹ 34 ʺ E) on June 28, 2021 .

Diagnosis. Size 127 - 151 × 29 - 35 μm after protargol impregnation (n = 5); body narrowly elliptical, flexible and slightly contractile, yellowish under low magnification, cytoplasm colorless, two types of cortical granules, type I yellow, 0.7 μm in diameter, type II colorless, bloodcell shaped, 1.8 μm in diameter; 65 - 78 macronuclear nodules; adoral zone of membranelles 34 - 49 μm long and consists of 36 - 59 adoral membranelles; 1 buccal cirrus; 9 - 14 frontal cirri in bicorona, 5 - 8 cirri in anterior corona and 4 - 6 cirri in posterior corona; 2 - 3 frontoterminal cirri; 22 - 34 midventral pairs; 35 - 49 left and 33 - 49 right marginal cirri; 3 - 4 transverse cirri; 4 dorsal kineties; caudal cirri lacking.

Distribution. China, Korea.

Remarks. The Korean population of Pseudokeronopsis parasongi is similar to the Chinese population in all aspects except the number of macronuclear nodules (65 - 78 vs. 135 - 168) ( Li and Xu, 2020). Li and Xu (2020) also reported a single contractile vacuole at 66% of body length and occasionally a second one at 25% in vivo; however, the anterior and posterior contractile vacuoles in the Korean population are slightly displaced posteriad (at 30% of body length) and anteriad (at 55% of body length), respectively. Pseudokeronopsis parasongi can be distinguished from P. carnea , P. erythrina , P. multinucleate , P. pararubra , and P. rubra by the body color (yellow vs. red or orange) and from P. elongata , P. similis , and P. decolor by the number of transverse cirri (3 - 4 vs. up to 6) ( Hu and Song, 2001; Song et al., 2002b; 2004; 2006; Hu et al., 2004; Shi et al., 2007; Baek et al., 2011; Chen et al., 2011; Li et al., 2017). On the other hand, P. parasongi resembles P. flava , P. flavicans , and P. songi in most features. However, P. parasongi occasionally possessing two contractile vacuoles, while in P. flava , P. flavicans , and P. songi has only one contractile vacuole. In addition, P. parasongi is similar to P. flava and P. flavicans in having yellow cortical granules, while in P. songi have dark-reddish cortical granules ( Song et al., 2002b; 2006; Li et al., 2017; Li and Xu, 2020).

Voucher slides. One slide with protargol-impregnated specimens was deposited at the National Institute of Biological Resources, Korea (NIBRPR0000111071).

Figures

Fig. 3. Pseudokeronopsis parasongi in life (A-C) and after protargol impregnation (D, E). A, B, Dorsal (A) and lateral (B) view showing the body shape and the two contractile vacuoles. C, Dorsal view showing the arrangement of the cortical granules; the yellow type I(arrowhead) and the colorless, blood cell shaped type II (arrow). D, E. Ventral (D) and dorsal (E) view showing the midventral pairs, the nuclear pattern and the four dorsal kineties. CV, contractile vacuole; FT, frontoterminal cirri; MA, macronuclear nodules; TC, transverse cirri. Scale bras 50 μm (A, B) and 20μm (D, E).