Predation of epipelic diatoms by the amphipod Corophium volutator and the polychaete Nereis diversicolor

Abstract

The effects of Corophium volutator (Pallas) and Nerefs djversicolor (0. F. hluller) on the dcnslties and specific compositions of epipel~c diatom assembldges were investigated experimentally, in the laboratory and in an estuarb-. In laboratory experiments cores contaming no macrofauna hdd sign~ficantly h ~g h e r dens~ties of d~dtonis than cores w ~t h C volutator and cores with N. d i r ~r s ~c o l o r after 8 d. In field exper~ments the densit~es of diatoms increased where C, volutator were removed, by spraying with insecticide, ~l n d wherc. .V diversicolor were prevented from surface deposit feeding, by the ~nsertion of porous mats under the \uriace. The mean d a ~l y rates uf consumption of diatonls by individual C'. volutator and N. d ~v e r s ~c o / o ~-