EN
Genetic variability of three sympatric crucian carp (Carassius carassius) populations from NW Poland was studied within a research project aimed at assessing the utility of those populations for stocking in inland waters. DNA samples were collected from 65 individuals. Restriction analysis was performed using 4 enzymes (HaeIII, HinfI, FspBI, TasI) of known restriction sites. The restriction profiles obtained were classi fied as belonging to a single haplotype (H-1). Selected DNA products were sequenced; the subsequent comparison made it possible to detect the presence of substitutions in the genome fragment analysed.