I have three Giant Danios: Two regular, and one albino. They seem to be very skittish around my other fish...except my White Skirt Tetras. The Danios and Tetras seem to enjoy swimming with each other all day long. Great beginner/starter fish!
I bought 2 Giant Danios for their liveliness and to cycle my tank. They would tag and I found this marvelous. I later added 6 Serpae Tetras thinking that this school would be cool. However, after two days they bickered among themselves and the Danios. Little did I know that this was contagious as the one Danio cruises the tank while the other hid in a corner. The dominant Danio would get chased by any one Serpae and did not care much, but the smaller danio would get chased from his corner by the other Danio or the Serpae currently defending that corner. I assume that once the serpae settle down the Danios will too, as I need to get some bottom feeders in there soon.
I thought these were nice fish to put with my other guys, but little did I know, I guess I bought the rabid kind. These guys eat everyone in my tank, so I thought I would buy some Cichlids to teach them a lesson. Once again I was wrong, they get along just fine, even now and then they fight for the top, but no trouble. Just as long as they are all the same size, they'll always get along.
Personally, I find these fish a waste of money. I hate to be so crude with my comment, but if this fish isn't bullying the other fish, it's bullying its own kind! I don't see too much in this fish, they don't seem to have personality to them, they just seem dull and hostile. No distinct eye-catching coloring to them either. Perhaps I'm missing out on something.
I bought two Large Danios as an addition to my community tank, which contained neon tetras, a gold gourami, blue gourami, a couple barbs, and pristella tetras. At first it was pretty bleak. The dominant Danio assumed control of the tank. All the fish hid in their respective corners, even the gouramies who were of decent size at the time. The fish, normally comfortable and non-skittish, became scared of their shadows (literally). I couldn't approach the tank without them hiding as far as possible. The one Danio would patrol the entire length of the aquarium like a shark, snapping at any fish that came close. After three of the yellow tetras died, I decided I needed a new fish to calm the Danio down. I introduced 2 kissing gouramis, and the Danio quietly took a seat in the back. All four gouramies get along great, and the danio, although still extremely active, is no longer terrorizing the other fish. I think he realized that if he doesn't behave, he's got four good sized gouramies on his hands, er, fins. They are very pretty fish, and very fun to watch.
I have been so angry at bullying giant danios I returned them to the pet store. That was right after they pestered my bala shark to death. I've since found suitable tankmates, and gotten some more. I have 3 giant danios in a 200 liter tank with a mature geophagus, a very large male angelfish, 3 moonlight gouramis, and a chinese algae eater. The giant danios provide movement and excitement, and so far none have been eaten by the geophagus. They're fast enough to outrun him. Their color is subtle, but color and movement were really needed in this quiet, moderately aggressive tank. There haven't been any deaths or serious injuries, so maybe this a good balance.