(Quennerstedt) Foissner & Wilbert (1981: 295, figs 2, 9–15)
Thompson (1965: 165), Aescht & Foissner (1992: 225), Foissner et al. (1994: 271), Song (2000: 303)
Lembus pusillus Quennerstedt (1869: 16, fig. 6)
Pseudocohnilembus persalinus Evans & Thompson (1964: 347, figs 1–6)Pseudocohnilembus longisetus Evans & Thompson (1964: 349, fig. 8)Pseudocohnilembus sp. (Thompson & Croom, 1978: 54, figs 13, 14)
In vivo 25–50 × 10–20 µm. Body slenderly ovoid, anteriorly narrowly rounded, posteriorly broadly rounded; oral area in anterior half of body. Somatic kineties 8–11; caudal cilium elongate. Adoral membranelles 1 and 2 and paroral membrane arranged as a longit-udinal double membrane; membranelle 3 forms a small patch of kinetosomes. Scutica composed of c. 10 kinetids (some dikinetids), posterior to cytostome. Macronucleus 1; micronucleus 1. Contractile vacuole slightly subterminal. Movement: moderately fast to fast, sometimes rotating rapidly, never resting. Prefers saprobic conditions.
Atlantic sector of the Southern Ocean (Thompson & Croom, 1978); soil on Nelly I., off Wilkes Land, East Antarctica (Thompson, 1965); cosmopolitan, also in freshwater and saline soils. Usually found under putrid conditions, often together with Uronema marinum .
There is considerable confusion regarding the taxonomy of the marine species of Pseudocohnilembus. Foissner & Wilbert (1981) synonymised P. persalinus with P. pusillus. Later, without providing a reason, Song (2000) treated P. persalinus as a separate species and considered P. longisetus and P. marinus Thompson (1966) to be synonymous. As important characters overlap between these ‘species’, they can be regarded as conspecific, with the possible exception of P. marinus.