Trout can look a bit gross when you see just how slimy it is. But, despite this gross feature of this fish it is actually a sign that it was a healthy specimen. When the jelly-like covering is not present you know that your trout has passed its prime.u003cbr/u003eu003cbr/u003eThis jelly film around the trout is designed to keep the trout safe from bacterial and fungal infection while they are alive. It is also something that they use to help them swim through the water more effectively.