| The only hitherto known freshwater acoelan, Oligochoerus limnophilus, has been fully described by Ax & Dörjes (1966). It has been recorded from habitats of different European rivers: Elbe, Ilmenau, Lahn, Main, Mosel and Donau (Kothé, 1961, 1962; Kothé & Sturz, 1963; An der Lan, 1964) where it prefers to settle on artificial stone embankments and is absent from typical lenitic regions and in river parts with a high organic pollution. The species has also been recorded from irrigation canals of rice fields in the Camargue (leg. U. Graefe). Ax & Dörjes (1966) suppose that O. limnophilus emigrated during postglacial periods out of the ponto-caspian area into their new environments because all the other species of the genus have been found in the... |
