Molecular phylogeny of some European heteronemertean (Nemertea) species and the monophyletic status of Riseriellus, Lineus, and Micrura

The 16S rRNA mitochondrial gene was used to reconstruct the relationships a mong 10 heteronemertean species (subclass Heteronemertea, phylum Nemertea); Lineus ruber and L. viridis are represented by more than one specimen to a ssess intraspecific variation in these enigmatic species, and the analysis includes in total 14 terminal taxa incorporating one palaeonemertean specie s (Tubulanus annulatus) for outgroup rooting. The aligned sequences were su bjected to maximum parsimony, maximum-likelihood, and neighbor-joining anal yses to estimate the phylogenetic relationship of the species. The results were concordant from all analyses and indicate that neither Lineus nor Micr ura are monophyletic taxa, and that there is no support from a phylogenetic point of view to establish the monotypic genus Riseriellus. (C) 1998 Acade mic Press.