“…Tarn River (Bou, 1979), RhGne River (Gibert et al, 1977), Danube River (Danielopol, 1976), Save River (Mestrov et al, 1983). A first explanation of these observations can be related to the well-documented effects of the industrial pollution of the Rhine River (Conrath et al, 1977;Kinzelbach, 1978;Dinh et al, 1981;Friedrich and Miiller, 1984;Behra, 1986;Zilliox, 1986;Schiller, 1990). A second hypothesis can be drawn from the comparison with the present knowledge of the River RhGne's interstitial communities.…”