I have one of these little fellows(I named him seymore), it's about 4 inches long. This one is lazier than any of the puffers I have had before, he just kind of lays around until I feed him. He likes krill and pieces of shrimp. When I first got him he was very shy and I had difficulty getting him to eat anything. I started him on clams and muscles. After about a month he finally started to eat other things. This reluctance to feed is contrary to most other puffers I have kept. they are all greedy messy eaters. In addition to the mbu I also have a 7" guinea fowl puffer that is like a dog following me around trying to get me to feed it and I have a porcupine puffer about 6" named bumble.