| Genera belonging to the family Euplotidae (Curds et al., 1983) are recognized by the following common characters: right marginal cirri absent, ciliatures highly developed or differentiated, all the cirral anlagen occur de novo, oral primordium formed within a subcortical pouch and most members with special silverline system. Though several revisions had been made during last decades and a lot of morphotypes are well studied, the phylogeny and evolution within these organisms remains unclear up to date and need further, reasonable comparisons and investigations.
Using data obtained from morphological examination (protargol or Chatton Lwoff staining method) in interphase and from the binary fission, this paper presents a tentative scheme of the systematic arrangements among the 11 genera dealt with in this study. The possible phylogenetic relationships are discussed with the methods of fuzzy cluster and cladistic analysis (apomorph-plesiomorph). The results indicate that seven groups can be divided according to the deriving sequence during the phylogenetic development. The order is: Gastrocirrhus, Swedmarkia-Discocephalus, Uronychia, Diophrys, Euplotidium-Certesia, Cytharoides-Euplotes, Aspidisco-Euplotaspis.
Morphological and morphogenetical data suggest that they can be placed into two higher taxa: Gastrocirrhur, Discocephalus and Swedmarkia belonging to the family Gastrocirrhidae Fauré-Fremiet, 1961, and the rest to the family Euplotidae Ehrenberg, 1838. |
