My male dolphin plecostomus has started swimming in the middle of the tank with my African Cichlids. He has also stopped eating algae wafers. He now swims up to the surface and swims upside-down to eat the cichlid food instead of his algae wafers. He has also shown cichlid mating behavior. It seems he thinks he is a cichlid. Any thoughts on why this is happening? My last pleco did not do this.