Morphological Investigations on Some Free Living Ciliates (Protozoa, Ciliophora) from China Sea with Description of a New Hypotrichous Genus, Hemigastrostyla nov. gen.

Abstract

2 heterotrichous and 9 hypotrichous ciliates including one new genus collected from the Yellow Sea and the Bohai Bay, north-eastern China are morphologically investigated based on living observations and using various silver impregnation methods: Protocruzia contraxMansfeld, 1923; Condylostoma magnumSpiegel, 1926; Holosticha mancaKahl, 1932; Oxytricha saltans (Cohn, 1866); Hemigastrostyla enigmatica (Dragesco & Dragesco-Kernéis, 1986) nov. gen., nov. comb.; Uronychia setigeraCalkins, 1902; Uronychia binucleataYoung, 1922; Uronychia transfuga (Müller, 1786); Euplotes minutaYocum, 1930; Aspidisca steini (Buddenbrock, 1920); Aspidisca leptaspisFresenius, 1865. Morphological characteristics and taxonomic position of all known Uronychia-species are briefly compared and discussed. About 3 Protocruzia-, 5 Uronychia- and 12 Aspidisca-species are considered as junior synonyms according to the results of our current studies. The hypotrich, Hemigastrostyla nov. gen., might be assigned to the family Oxytrichidae. Diagnosis of this new genus: body slightly cephalized; mostly 8–10 frontal, 5 ventral and a few extra lateroventral cirri which possibly derive from the 6th (right-most) cirral anlage during morphogenesis; caudal cirri present. Marine or brackish water forms. It is recognised from other oxytrichids by the cephalized body shape and possessing extra lateroventral cirri right to the transverse ones.