Yes...my 12 year old Aussie is not over 4'...some things I've read say they can get 4-5', but that's gotta take a while...they start out pretty small & even a great eater like mine isn't growing that fast. A 40 gal tank is perfect for one of these. Not the fanciest bright colors but a win for ease of care & personality. Mine is a dark greenish "granite phase"& she has real nice iridescence too...when I've done "meet & greets" with her, she was very much admired, as well as docile being held by total strangers. An excellent choice IMO.