My Zebra Danio Is A Big Bully!

[rebrn]

OK so a week ago I added my fish to my large 55 gallon. I have a large school of Zebra Danio (16 total 4 regular and 12 glo fish), a school of Cherry Barbs (4 males and 8 females) and 2 Pearl Gourmais (one male one female). All was going fine, the Zebras were schooling together, the Cherries were schooling together, and the 2 Gourmais were by themselves. A couple of days later I awoke to find the the Cherry school and the Zebra school have joined forces and are now one large (loose) school, I thought no big deal, now it looks like I have one giant school, actually kind of cool. Well for the last couple of days, one of the regular Zebras have broken away from the pack and has taken complete possession of one of the tank ornaments. He spends his (well I think it is a male but could be wrong) entire day guarding this ornament and chasing all the other fish away except the 2 Gourmais (they sleep in it). It is just so funny, any fish, except the Gourmais that come near he chases all the way to the other end of the tank, just to discover when he comes back all the other zebras and cherries are all over it. I don't know what it is about this particular ornament, but he has claimed it for himself, and will only share with the Gourmais. It is just so funny to watch.