The researchers studied how different diets and temperatures affect the fat composition of steelhead trout muscles. They fed the fish different diets with varying omega-6 to omega-3 fatty acid ratios and changed the temperature over 12 weeks. The diets didn't affect growth or total polyunsaturated fats, but individual fatty acids changed. Higher temperatures increased total fats and saturated fats, while decreasing monounsaturated and certain polyunsaturated fats. The omega-6 to omega-3 ratio was lowest at 18.0°C. These changes have important implications for fish nutrition, food quality, and aquafeeds.