The common snappers that are in the pond with the other local water turtles have access to food daily,In the past I have had alligator snappers, one large adult that was fed whole fish either blue or rock, once a week. she would take them right from your hand very gently.There was a guy in DC that raised it from a baby, and finally decided it was to big for him to keep. it was very docile when in the water.The younger ones I sorta fed them at different intervals depending on the appetite of the individual,and what type of food they were eating. If they didn't get so big and it wasn't so cold here in the winter I'd still have some,they are a pain to house in cold weather when they grow up.
My friend has one now and he feeds it every day. It's an alligator snapper. I never see it move. It just sits next to a big rock and waits for the fish to pass by, and then it "zaps" it. It's really cool looking, but kind of boring to me.