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Many invertebrates react to the actual presence and/or to chemical cues from predators. However, there is lack of information on the interrelationship of different cues triggering the antipredator response. In a series of aquarium experiments we investigated to which extent the antipredator response of a freshwater amphipod (Gammarus roeseli), i.e. seeking refuge in coarse substrate, is influenced by the actual presence of a natural fish predator (the ruffe, Gymnocephalus cernuus) including mechanical and visual cues, purely chemical cues, as well as the thickness of the sediment layer. Presence of Gammarus roeselion the substrate surface and activity was videotaped under different conditions and evaluated according to a standard protocol. Even without fish present and without fish chemicals Gammarus roeselimoved into the substrate because of thigmotactic behavior. The presence of ruffe accelerated this phenomenon and fish odor elicited weaker responses. Gammarus roeseliwas able to recognize the approach of fish predators both visually and/or mechanically.