Epistylis obliqua Sommer, 1951

Abibulaeva, Alie, Yalçin, Çağri, Durucan, Furkan & Dovgal, Igor, 2023, New record of Epistylis obliqua Sommer, 1951 (Ciliophora, Peritrichia) on aquatic mite Unionicola minor (Soar 1900) (Acari, Hydrachnidia), Zootaxa 5352 (2), pp. 279-283 : 280-281

Epistylis obliqua Sommer, 1951

( Fig. 1 A–C & Fig. 2 A–B )

Improved diagnosis: Colony alternating branched, short umbrella-shaped. The zooids are attached to the ends of a stalk branches. Contracted colony have a spherical shape. The stalk branching usually stepped ( Fig. 2 ). All ends of branches are very short and only the upper ones are occupied by zooids. Number of zooids per colony is 6–9. Zooids 45–52 µm long × 19–22 µm wide in vivo (72 µm long × 45–50 µm wide after Sommer, 1951), elongate vaseshaped and constricted below the thick peristomial lip. Primary stalk of colony short to moderately long, measuring approximately 80 µm long. According to Sommer (1951), length of primary stalk reaches values 260 µm. Stalk diameter varies from 6 to 9 µm (11 µm after Sommer, 1951).

Zooids of E. obliqua are asymmetrically built and taping conically towards the stalk. The protrusion of the peristome is completely elongated at the orifice of the peristome and inverted on the opposite side. It rarely reaches its maximum width of the body.

Peristomal lip single-layered, is slightly everted with a size ranging from 20 to 25 µm in width and from 5 to 6 µm in height. The peristomal disc is wide, flat, and barely rises when the ciliate is turned. The edge of the peristome is furnished with numerous small and narrow folds. The wide, then tapering, elegantly shaped long infundibulum is characteristic of the genus ( Fig. 2 A–B ). The contractile vacuole is positioned in the anterior quarter of the cell body. The C-shaped macronucleus lies in the adoral half of the zooid and oriented along longitudinal axis of the cell body. The pellicle is slightly transversally striated.

Type locality: The Lake Plön in the district of Plön Germany ( Sommer, 1951) .

Other localities: Ijburg, Amsterdam ( the Netherlands), present report.

Hosts: freshwater mite ( Sommer, 1951), Unionicola minor (Soar 1900) , present report.

Figures

FIGURE 1. Epistylis obliqua on Unionicola minor A—Habitus ventral B—Magnified dark field view of Epistylis obliqua colonies C—Magnified view of E. obliqua on the first leg of the mite. Scale bars: A = 200 µm, B= 100 µm, C= 50 µm.

FIGURE 2. Schematic drawings of Epistylis obliqua. A—after Sommer (1951); B—original. Scale bar: 50 µm.