Thanks for doing your job!
The fish are the same but aquarium folks and pond folks generally have very different goals.
Aquarium people treat their fish like pets. What I make for aquarium fish is health food for fish. It contains plenty of protein and enough energy (starch and fat) for them to breed and live long healthy lives. Excess fat and starch leads to fatty liver condition which many biologists believe shortens the fish's lifespan. In a nut shell feeding our food makes them feel good about themselves. Fish are much easier to understand than humans. One of the reasons that I have a business partner is that if I believe that I will learn something beneficial I will net a live fish from the tank and dissect it immediately.
Pond fish are either mean't to be eaten or to be grown to trophy size. In either case you want fat fish. I spoke with the Head of Nutrition at Auburn's Fisheries Department about having some fish's livers dissected and examined about a year ago. He told me that they had caught catfish being fed grain based food from a pond and that they had fatty liver condition but were otherwise healthy. The point being fish mean't to be eaten it really doesn't matter.
Clay
