The questiion also is, where does ur wolf hang out. Mala are weird. Some hang out on top of stuff on the tippy top of the tank like mine does, some hang out on the floor. Mine tends to sleep on the top then on weird days on the floor but never in hiding. Which is why I won't add anything to the tank. I'm. He seems to make sure he takes up the whole tank, but then again if ur running a 180g there is alot room for them, but I have also noicted if there is. A fish in my wolfs tank he wakes up and swims with them, when he got a koi that was to big to be eaten he used to swim with it but the got pissed after. A couple days and ripped his. Back half off and went to his sleeping spot and watched the koi die. It all depends on the fish, it seems from looking around the site, all the wolfs that have tankmates are larger and where in the tank first and the wolf was a baby whem put in the tank, so it grew up with tank mates.