The fatty acid composition of carp changes during winter, affecting their ability to survive in cold temperatures. Starvation did not impact the fatty acids in the fish muscles, but the ratio of saturated to unsaturated fatty acids decreased in low temperatures. Hybrid carp saw an increase in monoethylenic acids and a decrease in docosahexenoic acid (DHA) during winter. These changes may impact the carp's ability to survive the winter season.