Growth of pikeperch Sander lucioperca in the eutrophic and clay-turbid Lake Sahajärvi, Southern Finland, was extremely slow in comparison with other lakes at similar latitudes. The most important food item in July was phantom midge larvae Chaoborus flavicans for all sizes of S. lucioperca (239-423 mm total length L(T)), while later, in August and September, the diet of S. lucioperca (149-407 mm L(T)) consisted of small (30-100 mm L(T)) perch Perca fluviatilis, ruffe Gymnocephalus cernuus and roach Rutilus rutilus.