fish fighting !

Question
I just got an african knife fish, it is 4 inches long, I bought it an hour ago, I put it in my tank recently, and it keeps on fighting with my gold grouami which is about 4 inches long as well, it also picks on my largest angelfish , what can I do ?

Answer
Joseph, He is trying to establish ownership in the tank. They are normally not too aggressive but since he is new, they fish will have some issues. Keep an eye on them and if it gets too aggressive you might have to remove him. Sometimes fish that normally get along will fight. Each fish is different.