Litonotus cygnus (Müller, 1773) Kahl, 1931

Vďačný, Peter & Rajter, Ľubomír, 2014, An annotated and revised checklist of pleurostome ciliates (Protista: Ciliophora: Litostomatea) from Slovakia, Central Europe, Zootaxa 3760 (4), pp. 501-521 : 510-511

Litonotus cygnus (Müller, 1773) Kahl, 1931

Lionotus cygnus — Bílý et al. 1952: 81; Hanuška 1962: 822; Hanuška 1967: 927.

Litonotus cygnus — Matis 1977: 25; Tirjaková & Matis 1987: 9; Matis 1988: 58; Matis & Straková-Striešková 1991: 114; Matis & Tirjaková 1992: 52; Tirjaková 1993: 134; Matis & Tirjaková 1994: 58; Tirjaková 1997a: 16; Tirjaková 1997b: 27; Tirjaková 1998: 16; Tirjaková 2001: 15; Baláži & Matis 2002a: 155; Baláži & Matis 2002b: 9; Tirjaková 2003a: 37; Tirjaková 2003b: 20; Tirjaková & Stloukal 2004: 17; Tirjaková 2006: 9; Tirjaková & Vďačný 2013a: 670.

Nomenclature. Matis (1977) misdated L. cygnus with year 1786, and Matis (1988) and Matis & Tirjaková (1992) with year 1776. Tirjaková & Stloukal (2004) incorrectly used Foissner et al. (1995) as combining authors. However, Kahl (1931) already combined this species with the genus Litonotus , erroneously using “ Lionotus (Vibrio) cygnus ( O. F. Müller), 1776 ”.

Main morphological characters (according to Foissner et al. 1995). Length 200–300 µm in vivo. Body fusiform, posteriorly tail-like when fully extended; highly contractile. Two macronuclear nodules with a single micronucleus in between. Contractile vacuole distinctly subterminal. Extrusomes rod-like and curved, about 6–8 µm long, attached along whole length of oral bulge and scattered in cytoplasm. Somatic ciliary pattern Litonotus - like; 6–13 right and about 5 left kineties.

Distribution. Litonotus cygnus was recorded in the benthos from the Hornád River near the village of Kubachy ( Bílý et al. 1952); in the Nitra River and its two tributaries, the Handlovka stream and the Žitava River ( Hanuška 1962); in the rivers Hnilec and Hornád as well as in their tributaries ( Hanuška 1967); in the littoral of the water reservoir of Zemplínska Šírava during fall and spring ( Matis 1977); in submerged, wet, and moist mosses from Slovenský Raj ( Tirjaková & Matis 1987); in organic mud from activated sludge plants in Bratislava ( Matis 1988); in the Teplý potok brook and thermal lakes in the Bojnice Spa at 16–42 °C and pH 5.6–7.5 ( Matis & Straková-Striešková 1991); in the backwaters of the Danube River in Čičov ( Matis & Tirjaková 1992); in the periphyton and benthos of the Turiec River ( Tirjaková 1993); in small lakes in the inundation zone of the Morava River ( Matis & Tirjaková 1994); in debris of the spring area below the Veľký Javorník, Malé Karpaty Mts ( Tirjaková 1997a, Tirjaková & Stloukal 2004); in oligotrophic streams in the National Nature Reserve Rozsutec, Malá Fatra Mts ( Tirjaková 1997b); in the benthos from tributaries of the Hron River ( Tirjaková 1998); in the benthos from the Ružičkov prameň spring, High Tatra Mts ( Tirjaková 2001); in the pelagial of the Morava River and Váh River near Komárno ( Baláži & Matis 2002a); in the benthos from various localities in the Gidra River ( Tirjaková 2003a); in the Stupavský potok brook ( Tirjaková 2003b); in the spring area of the Hron River ( Tirjaková 2006); in the sediment from the littoral zone of the upper Váh River ( Tirjaková & Vďačný 2013a).