4 days ago i added 2 baby silver arowanas each about 5-6" in my 180 gal tank. But for the last 2 days i noticed my one silver arowana is chasing other and if he get the other then he bites other.Where as the other is always trying to escape from that attacker.And it causes some loss of fins of that victim.I am feeding them guppys and both are eating though the attacker is eating much more than the other. I want to know why he is behaving like this & what i need to do now?