Alimentary tracts of 692 Prussian carp were examined. Diet components were identified using the keys published by Rybak [1971] and Pennak [1953]. The Prussian carp food was found to consist of 19 items identified to species, genus, or family/order. The food composition was also characterised by calculating contributions of individual food items to the total number of food items (UL), frequency of occurrence of each item (CZW), and each item’s contribution to the gut content weight. The fish feeding intensity was presented using a per cent general consumption index. The fish were found to have fed at the highest intensity in July, the lowest feeding intensity being recorded in November and December. The length-weight relationship of the Prussian carp examined was analysed as well and described as W = 0.0355L^3.017. Fish condition in various periods of time was assessed using the Fulton and Le Cren coefficients for whole fish and Clark’s method for gutted fish. The lowest values of the Fulton and Le Cren coefficients were typical of the Prussian carp caught in the Szczecin Lagoon (April 2000) and Lake Zbęchy (November 2000); the lowest condition coefficients calculated using Clark’s method were those found in the fish from Lake Wonieść (September 2002). The highest Fulton and Le Cren coefficientswere recorded in the Lake Zbęchy Prussian carp (November 2000); similarly, the Lake Zbęchy fish, when gutted, showed the highest Clark coefficients.

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