Morphological and Morphogenetic Redescriptions and SSU rRNA Gene-based Phylogeny of the Poorly-known Species Euplotes amieti Dragesco, 1970 (Ciliophora, Euplotida)

This article investigates the morphology and morphogenesis during binary fission of a Chinese population of Euplotes amieti Dragesco, 1970, a fresh water form which has previously not been well defined. This organism is morphologically very similar to the well-known Euplotes eurystomus but differs from the latter both in the number of dorsal kineties and the molecular data. According to the information obtained, it is characterized by a combination of features including nine frontoventral cirri, ca. 60 membranelles, 12-15 dorsal kineties, a macronucleus in the shape of the number 3, and a double-eurystomus' type of silverline system. In this study, the SSU rRNA gene was sequenced for the first time, and phylogenetic analyses indicated that it is closely related to the eurystomus-aediculatus-woodruffi- complex. Considering the extreme similarities in morphology between E. amieti and E. eurystomus, the authors believe that the four sequences under the name of Euplotes eurystomus are very likely from misidentified material; that is, they represent different populations of Euplotes amieti.