Strombidium Claparède and Lachmann, 1859

Wilbert, Norbert & Song, Weibo, 2005, New contributions to the marine benthic ciliates from the Antarctic area, including description of seven new species (Protozoa, Ciliophora), Journal of Natural History 39 (13), pp. 935-973 : 953

Genus Strombidium Claparède and Lachmann, 1859

This well-known, species-rich genus has typical family characters: adoral zone of membranelles generally consisting of collar and buccal parts and two somatic kineties: circularly arranged girdle/equatorial kinety and the short, subcaudally positioned ventral kinety, although the former may have a small gap, i.e. not be completely continuous. Unlike Strombidium , the related genus Spirostrombidium established by Jankowski (1978) is characterized by the differently arranged somatic kineties, i.e. the girdle (equatorial) kinety does not encircle the equatorial area, but is opened and extends spirally to the caudal region, often very close and parallel to the short ventral kinety. Thus, some members of this genus seem to possess only one somatic kinety when observed superficially ( Petz et al. 1995; Song and Packroff 1997; Song et al. 1999, 2000).

Based on the pattern of the girdle kinety, the most critical feature to separate the two genera is the posterior end of the equatorial kinety which extends to the caudal area and is parallel to the ventral one versus terminates anterior to the proximal end of ventral kinety.

According to this definition, the new form we obtained should be classified within the genus Strombidium .