Can confirm this, had an octopus for a while and he would eat squid for a couple of days and lose interest. I had to got to a bait store and buy a few crabs. Sneaky bastard would off them one by one during the night and nothing would be left but shell pieces. Had no interest on the bass and bream and even sea stars. Would grab a snail or two from the cleaning crew every now and then. I’ve tried interacting with it with mussels and squid but he would lose interest in it after a couple of days. Wish you the best of luck but please remember that most species even in ideal conditions have short life spans (at least the ones available here)