KillerFish kill everything they encounter. They then eat the corpse and grow. They are the longest lasting fish when put in with almost any ratio of gillfish and fish. GillFish grow and eat when they encounter smaller fish and shrink when they encounter larger more intimidating fish. Their only competitor is the killer fish and the competition always seems to be won by the stronger and larger killer fish.
Fish mate with every fish they can.
They are promiscuous little devils. Unfortunately with all their experience in mating they still can keep there population alive. They end up starving or being killed by thegill fish and killer fish. They need to become more aggressive in areas besides mating.