Phylogenetic position and notes on the ultrastructure of Sappinia diploidea (Thecamoebidae)

Abstract

Summary An unusual amoeba, Sappinia diploidea, possessing diplokaryonlike nuclear apparatus and a complex life cycle, was isolated from the bark of trees and a freshwater pond, identified and reinvestigated. The phylogenetic analysis based on SSU rRNA gene sequences shows close relatedness of this species to the members of the genus Thecamoeba. It suggests the existence of the monophyletic family Thecamoebidae, comprising the genera Thecamoeba and Sappinia, but not comprising Dermamoeba algensis, whose phylogenetic position remains illresolved. Until now there was no laboratory culture of this interesting species; as a result of the present finding, a strain of Sappinia diploidea is deposited with CCAP (UK) and is available for further studies; a neotype is established for this species.