[jdm68]

So I've got five Long-Fin Zebra Danios, and today while looking at them, I noticed one has picked up a very golden hue across his (I think) whole body. Not an illness looking hue, just like the silvery-white in his body is now yellowish-gold. It also seems to be accompanied by a little more agression as he is VERY vigorously chasing around his tankmates. Normally it is one of the females (I think) that does the chasing. Is this a normal thing or should I be concerned about his health? Possibly a preparation for breeding?

 

[dwc13]

Zebra Danios are always on the move and quite fast swimmers. Depending upon movement, angles, room lighting, and aquarium lighting (and assuming no color/clouding issues with water from algae, tannins, floating debris, etc.), their colors can appear different at various times of the day. Nothing unusual there. As far as perceived heightened aggression of one of your fish, Zebra Danios love playing but from what I have observed they are somewhat more calm in larger numbers (more than 5). At least until you throw in some high quality sinking wafers...and then it's a game of rugby, as best I can tell.

FWIW, five is the minimum number of Zebra Danios I would keep (long-term) in an aquarium. I took 3 Zebra Danios from a well-established 20H tank with plants and used them to help cycle a 45G aquarium with plants. That left 5 Zebra Danios in the 20H. Prior to the relocation, all 8 had been together in the 20H for at least 10 months. The next day, the 5 remaining in the 20H were noticeably more active, which is saying something b/c they are usually pretty active. Perhaps they were looking for their "missing" buddies. I ended up taking the Bio-Wheel from the 20H and using it in the 45G later that day and reunited all 8 Zebra Danios. All 11 (now) are very happy with their much larger new home.

 

[jdm68]

Well, I observed the color over a period of time and with many different angles, positions under the light, and while moving, so it was definitely a change in color. I also looked at him next to his mates to compare color. However, I just got back home, and the color is gone. There are two D's with longer, flowier fins and it was one of them that was a different color, and now they are both the same.
I agree, 5 is the least I'd keep. I bought 3 initially to cycle, and they seemed fine, just not real schooley. I decided to pick up a couple more, and they all seem pretty content. That said, I will probably get 5 in the future. Just waiting until after the cycle for the four peppered Corys I put in is complete. Those are some pretty cool fish too, a little bit skittish though...

 

[dwc13]

Did you give them a different food or do a recent major water change? Sometimes either can condition a fish for breeding.

What size tank are your Danios & Corys in? At the present time, I've got 11 Zebra Danios and 4 Julii Corys in my 45G tank. Just added the Corys on Sunday and they're having a good ol' time swimming about their new home. I'll probably get 2 or 4 more in the future, as additional fish are added.

 

[jdm68]

Sorry for the slow reply. I've got a 45g as well. Since the last post, I've added one more ZD, for a total of six, six Neon Tetras, and three black Kuhlis. Those guys are crazy to watch. They just all of a sudden go nuts and swim like crazy up and down the walls, across the front of the tank, back to the other side, up to the surface, then down to a plant for a 15 second rest, then back to swimming like crazy. Hopefully they'll calm down after a couple days...

 

[Grow_Explore]

So I've got five Long-Fin Zebra Danios, and today while looking at them, I noticed one has picked up a very golden hue across his (I think) whole body. Not an illness looking hue, just like the silvery-white in his body is now yellowish-gold. It also seems to be accompanied by a little more agression as he is VERY vigorously chasing around his tankmates. Normally it is one of the females (I think) that does the chasing. Is this a normal thing or should I be concerned about his health? Possibly a preparation for breeding?

I have the same thing going down! I noticed the craziness from across the room so I came over to my tank to see 3 danios just absolutely having the zooomies. They were tail slapping plants, darting from one end to the other, swimming in areas they don’t typically go, all three of them sparing together. I get that danios act this way but this was cranked up to 100. As I watched I noticed the three zooming had that golden hue to them while the other two danios that were acting normal were still the normal black hue.

recent change to tank. Moved sponge filter, propagated, plants, added co2 injection

 

[LidijaPN]

You might not get a reply here as you resurrected a thread from 2011