Could someone put my mind to rest. I had a small group of Pearl Danios, 4, and went to purchase a few more so as to create a proper group of seven. I have now realized one my new group is a Zebra Danio. It is playing merrily with the others, but will it need more Zebras to be truly happy. They will be getting their own 100ltr tank in the next few months as they are show stoppers, but I would hate to think the Zebra actually felt lonely. Of course when they move I will have to console my tiny ember tetras who follow them everywhere!