Epistylis pygmaeum (Ehrenberg, 1838) Foissner,, 1999

Kim, Ji Hye & Jung, Atef Omar and Jae-Ho, 2020, Brief description of 18 newly recorded ciliate species from soil and inland waters (Protozoa, Ciliophora) in South Korea, Journal of Species Research 9 (3), pp. 251-268 : 266

17. Epistylis pygmaeum (Ehrenberg, 1838) Foissner,

Berger & Schaumburg, 1999 ( Fig. 17 )

Material examined. Freshwater with some debris collected from Domun-dong, Sangju-si, Gyeongsangbuk-do, Korea (N 36°26 ʹ 8.09 ʺ, E 128°14 ʹ 29.96 ʺ) on 14 May 2019 .

Diagnosis. Colony dichotomously branching, usually short epistylid stalk; zooid size 35 - 40 × 21 - 27 μm in vivo; zooid shape barrel shape to cylindrical, rarely campanulate; peristomial lip width 21 - 22 μm in vivo (n = 3). Single contractile vacuole located on ventral side. Transverse silverlines, 16 - 23 striations between anterior end and aboral ciliary wreath, 11 - 15 striations between aboral ciliary wreath and scopula. Infundibular polykinety 3 composed of two rows.

Distribution. Cosmopolitan.

Remarks. Epistylis pygmaeum is a common epizoic peritrich. The Korean population of E. pygmaeum corresponds to other populations. Epistylis pygmaeum is similar to E. anastatica , but mainly differs in the size of zooid (35 - 40 μm vs. 60 - 100 μm) ( Foissner et al., 1999).

Voucher slides. Two slides with protargol-impregnated specimens were deposited at the Nakdonggang National Institute of Biological Resources (NNIBRPR11672, NNIBRPR11673).

Figures

Fig. 17. Epistylis pygmaeum from life (A-C) and after protargol impregnation (D, E). A. Epibiotic habitat of E. pygmaeum. B. Body shape and contractile vacuole in vivo. C. Dichotomously branched stalk. D. Infundibular polykinety 1-3. E. Macronucleus and silverline systems. Scale bars=200 μm (A); 50μm (B); 20 μm (D); 10 μm(E).