I have a couple of O's, one of my personal favorites. They grow FAST - I saw at least 1" per month growth til about 9-10" long. They will constantly beg for food so watch out for overeating, they do like a variety of food - mine get pellets, shrimp/krill and try to steal whatever I put in for my plecos. They will try to jump out, especially when you are feeding them and have the lid open. They will eat fish that can fit in their mouths so watch out if you have tankmates. Lots of personality with these guys, they will sulk - when I moved one to a larger tank he laid on his side for a couple days before he forgave me for moving him.