Intraspecific variation in nemerteans (Nemertea): synonymization of genera Paroerstedia and Oerstediella with Oerstedia



Intraspecific variation in internal morphological charactcrs is substantial in many nemertean species, mainly due to the tendency for specimens to contract during fixation. It is shown that variation within the type species for the genus Oerstedia, O. dorsalis (Abildgaard, 1806), encompasses all the character states that have been used to erect the two related genera Oerstediella and Paroerstedia. These genera are synonymized with Oerstedia, and the validity of species previously assigned to these genera is discussed.