I think its very possible to have two different personalities in fish there are always going to be fish that are more aggresive or more peaceful. A lot could be due to things that happened to them when they were young or perhaps even genetics. For instance maybe in some locations its better for surival if the fish do not become hostile towards other fish because time is better spent looking for food to survive. Where as were food is abundant they maybe more aggresive because they can afford to set up a hierarchy. This is just a theory who knows but i do know that some fish tend to be calmer than others. Like my LMB lives in pretty much peace with a bluegill while a friend of mines bass im pretty sure would either eat it or just pick on it so much. Who knows??
