In the marine environment associations between picoplankton and copepods are very important not only for the lifestyle of these animals, but also for marine ecosystems and human health. In the present study we investigated the biofouling of Tigriopus fulvus in culture and possible effects of this colonization by means of scanning electron microscopy and epifluorescence microscopy. These investigations show that T. fulvus is heavily and not uniformly colonized by bacteria and algae.