Not so much the nigers, but the pork might if hes on the aggressive side. Most of the time they are absentminded, got bette things to do, ya know? Like rest on the bottom, swim up and down the side of the tank, sleep, swim up and down, and then eat and sleep some more. BUT, since yer tank is already pretty full, it would be illadvised to give you the go on that one. Yer tank is already quite stocked and i wouldnt risk putting anything else on that bioload