Seasonal changes affect the types of fats in the muscles of Mesopotamian catfish in the Tigris River. Polyunsaturated and monounsaturated fats are the most important types found. The main fats in the muscles are palmitic acid, oleic acid, linoleic acid, and docosahexanoic acid. The ratio of omega-3 to omega-6 fats varies throughout the seasons. Omega-3 fats are highest in winter. The types of fats in the muscles are significantly influenced by the time of year.