Fishy Situation

OK...so I'm still a little disturbed about what just happened here. "M" and I walk into the living room to find "B" standing in front of our fish tank. (We just sat this tank up a couple days ago...we have/had 9 gold fish and 1 algae eater) The lid is up and the front of the tank is wet along with the bar where it's sitting. As I went to shut the lid, a horrendous fish smell smacked me in the face. As I'm looking at the tank, I see fish pieces laying on the bottom. I told "M" to come and look, that we have pieces. He's like what?? We then ask "B" what happened and he told us that he took the net, caught a fish, and chopped it up "so mommy, daddy, "c", and "b" could have fish for dinner. We're still not sure where the massacre took place. There are no pieces stuck to the net, on the bar, or in the floor. I am assuming that he maybe hit it up against the side of the tank for cornered it on the rocks and "chopped" it up that way??? As I'm standing there in complete aw, I'm thinking to myself that we have a little massacarist on our hands. I'm trying to figure out where he's seen someone chopping an animal or came up with the idea to do this. I often watch Food Network or Hell's Kitchen but Food Network doesn't chop up fish on tv (or what I've watched) and Hell's Kitchen comes on when he's in bed. He was very set on having this for dinner though. He was actually pretty proud of himself. We tried to explain that what he did was wrong. You can't chop up your pets. So, needless to say, we're getting rid of the tank until the boys are a little older.