My buddy has had a Bullhead in his fish tank for a little over a year that I caught from Wirth, the thing was probably 5 inches when I caught it and now it is about 10 inches, the Catfish will sit in its rock cave and be on the food by the time it gets 3/4 down the water column, you can immediately tell it can't see very well because it will hover about an inch off the bottom and just run its barbs (taste buds) along the bottom, when its barbs make contact or come close to food, it will raise up a bit, tilt down and snatch the food with a couple other gulps that snatch any other nearby food.
Scavenger type fish are what really interest me.