Zebra Danio Bullying
I just set up a ten gallon tank on Sunday (added the chemical that makes tap water okay, and PH neutralizer) and let it run until Tuesday, and I bought 3 zebra danios. I noticed from the beginning that one of the danios was chasing the other two, and I didn't think it was anything until today I took a closer look and saw his mouth opening and closing during his encounters with the other danios, so I assumed he was trying to bite them). I have been watching their fins since the start to make sure they weren't getting hurt, and so far all of their fins are in tact. One of the fish he bullies will fight back, but wont attack the other fish, and the other fish he bullies will just swim away. I don't know if this is normal behavior, if it has something to do with gender perhaps, or what I should\can do to stop it. Any help or input is much appreciated.