Zosterodasys minutus Gong et al. 2007

Zosterodasys minutus Gong et al., 2007

(Figs 8 A–F, I)

Chilodontopsis vorax (?) – Burkovsky 1970a: 54, fig. 9; Burkovsky 1970b: 187 (very likely a distinct species; see remarks). Zosterodasys minuta Gong et al., 2007: 307, figs 38–52.

Diagnosis. Size about 50–100 × 20–40 µm in vivo. Body shape obovate with left margin anteriorly indistinctly projecting. Macronucleus ellipsoidal to bowknot-shaped with three comparatively large (4–10 µm) globular micronuclei. Many scattered contractile vacuoles. About 34–55 ciliary rows; ventral kineties form a suture in meridional and posterior body half. Synhymenium completely encircles body. On average 11 (10–12) nematodesmal rods. Marine.

Type locality. Intertidal muddy sediments of Ganghwa Island, Incheon, Korea, E126°32' N37°35'.

Type material. One holotype slide with protargol-impregnated specimens was deposited in the Natural History Museum, London, UK (registration number 2007:03:09:3). One paratype slide with protargol-impregnated specimens was deposited in the Regional Research Center for Coast Environments of Yellow Sea, Inha University, Incheon, Korea (registration number G 06052003).

Etymology. The Latin adjective minut · us, - a, - um ([m, f, n]; minute) refers to the small size of the species.

Remarks. Under the Articles 30.2.4, 31.2 and 34.2 of the ICZN (1999) we mandatorily change the species group-name from minuta to minutus because Zosterodasys is masculine gender. Zosterodasys minutus is outstanding among marine congeners in having a suture formed by the ventral ciliary rows in the meridional and posterior body half. This peculiar feature was also found in the marine “ Chilodontopsis vorax (?)” of Burkovsky (1970a). However, Burkovsky’s species is much larger (130–160 × 46–50 µm vs. 50–100 × 20–40 µm) and has a higher number of the ciliary rows (50–80 vs. 34–55) as well as of the nematodesmal rods (16–18 vs. 10–12). Further, it displays only a single micronucleus with a size of 6 × 4 µm (vs. three micronuclei 4–10 µm in diameter).

Thus, Burkovsky’s species, which was found in the Kandalakša [Kandalaksha] Gulf in the White Sea, very likely represents a distinct species and is therefore not incorporated into the diagnosis of Z. minutus.