an ID a few years ago. Bought them at Wal-Mart and asked the guy there how big a tank I'd need for them(i thought they were real sharks and would get big) He said that in captivity they only grow to 6 inches and said my 40 gallon tank would be fine. Needless to say my id outgrew my tank quickly, luckily I had a friend to give him to. He put him in his 150 gallon tank with a few other fish, but he ended up dying after like 4 months or so.