Omega 3 is IN Krill Oil. There are different forms of Omega 3. The ones that are most important for your brain are DHA and EPA. These are found in fish oil, Cod Liver Oil and krill oil - but NOT in non-meat sources of Omega-3 like Flaxseed Oil and walnuts. Non-meat sources have ALA. ALA is not as biologically potent, but can be converted by the body into the other forms IF your body is healthy. Insulin-resistance, for instance, prevents your body from converting ALA very well. Krill oil is even more biologically available than fish oil - in other words, your body absorbs it better so you need less of it to have an effect. You also get lots of potent antioxidants from krill oil that you don't get from fish oil. Cod Liver Oil, of course, has the benefits of Vitamins D & A, which are great during colder months and are additional boosts to the immune system. (Fish & Krill in themselves are great for the immune system & the heart as well as your brain!!)
Hope this helps! Have a great day & great holidays! I'm really looking forward to my husband being off for a week!!