Hi there. I came across this site while looking up information on the Glofish I just bought. I have had everything in my tank set up and I started the cycle off with 5 glofish and one zebra danio. My question is can one fish (the zebra danio) dominate all the other fish to the point where they hide in the plants and decorations I have? When I removed the zebra danio and put her in the hospital tank to see how the other fish reacted they all came out of hiding and schooled again. Is this happening b/c she is the dominate female or could it be because she doesn't look like the other fish. (I'm new to the fish world and I am not sure how well fish can determine things like this)

Welcome to the forum Heather! You had to wait for me to approve your topic before you saw it.

Glofish are zebra danios with anemone genes added to theirs. As far as the fish are concerned, they're all the same species. They won't discriminate against each other either way. The single zebra danio may be dominant because he/she is older, healthier, or simply the odd man out since the other danios already know each other.

You can try a few things. Buy a little net breeder (not expensive) and put the zebra danio in there but in the tank with the glofish. Keep him there for a few days and then release him. He may be so happy to be free as to no longer bully the other fish. On the other hand, if the problem is that the glofish are shy, this will also reduce that problem.

Others suggest redoing the decor and moving things around but I doubt that would help much. How big is the tank? Another thing to try, if the tank is large enough, is to add more fish so that the tank dynamics change. New fish often hide.

Good luck!

I have been keeping zebra danio's for a while now (well over a year) and they do school together with my white cloud mountain minnows (i have 3 of each) they seem happy enough maybe you should try adding a few more zebra danio's i done this when i first got my minnows and it helped alot :)