Phylogenetic position of the Sphaeropleaceae (Chlorophyta)

The complete 18S rRNA gene sequences of four Sphaeroplea C.A. Agardh strains (Sphaeropleales, Sphaeropleaceae), two Atractomorpha Hoffman strains (Sphaeropleales, Sphaeropleaceae) and two Ankyra Fott strains (Chlorococcales, Characiaceae) were determined and subjected to phylogenetic analyses. The analyses indicated that all these taxa belong to a monophyletic lineage (Sphaeropleaceae) and are related to a group of chlorophycean algae comprising autosporic taxa and taxa that reproduce by zoospores which are characterized by directly opposed basal bodies. The taxonomic assignment of the Sphaeropleaceae as a family within the Sphaeropleales (Chlorophyta, Chlorophyceae) is discussed.