green brittles are reef safe. as far as that statement goes. but they can be fish eaters, they are great cleaners but they are one of the few starfish that are fast enough to catch fish, Usually when the fish is sleeping. So the statement should be, they are coral safe but not nessecarily fish safe. a lot of people keep them succesfully with fish just make sure its appetite doesnt make it need to eat fish, if you dont want the hassle of spot feeding it I reccomend getting a different type of brittle.