Danio bully help

[madly99]

Hi all,

I am a brand new tank owner and need a little help please. I'm concerned for the life of one of my zebra danios! I set up my 20G tank 4 days ago and added 3 zebra danios and 2 buenos aires tetras. Two of the danios keep chasing and nipping at the third. I thought it was just normal aggression that would work itself out, but this morning I noticed the poor fellow hanging out at the bottom of the tank at feeding time.

Am I being paranoid? Is there anything I can do? I thought of maybe adding more danios, having read that schooling might bring down the aggression, but I'm worried that a) he might end up with 4 fish picking on him instead of 2; or b) i'll do more harm to the tank and fish overall by adding more fish at this point. According to my last ammonia test, I'm somewhere between 0 and 0.25ppm. I can't separate him because I don't have another tank in which to put him.

Any advice would be greatly appreciated!

Thanks!
Melissa

[hungryhound]

Since you are still cycling the tank I would not add any more fish. Adding more fish will increase the chances that your fish will die from ammonia or nitrite poisoning.

My advise to you, while cold and heartless, is to let it play out while you are cycling as most of the fish in question will not make it, and your problem will be solved. To avoid subjecting fish to the problems of cycling you should check out the thread on fish less cycling.

Once the tank is cycled I believe that adding more fish would help.

In order to keep all of these fish alive you are most likely going to need to do a 25 precent water change every day to keep the ammonia and nitrite at safe levels. I would worry about that and then worry about aggression issues later.

[Chaindriven]

I am sorry that one of your Zebras isn't doing so well. I here is some information I found that should help.

Zebras are primarily surface dwelling fish that favor moving waters. Technically they are considered cold-water fish, preferring water in the 64-75 degree range. However, they will adapt to a wide range of water conditions. They should be provided with plenty of lighting and an open swimming space, together with some vegetation.
Caring for such a vibrant and active fish is not as easy as people may lead you to believe. Even though the zebra danio is a common fish, regularly found in tropical community tanks world wide, they do require something of a caring touch to make sure that they are both happy and healthy. Most people are not aware that the zebra danios' hyperactivity is actually a sign that they are slightly aggressive. They are schooling fish, and if they are not kept in sufficient numbers, then their schooling behavior will mix with their aggression and lead to fin-nipping and even attack on tank mates. A good school size for zebra danios is a minimum of five fish, with a preference for nine or ten. If you watch a well housed school of danios, you will quickly see that the males will occasionally display fight. It is this behavior that translates to aggression and fin nipping when they are improperly housed. Typically, the display fights involve nothing more than two male danios staring at each other and straightening their pectoral fins. It will last for about twenty seconds until one of the danios gets scared off, forgets what it is doing or simply gets bored.
If you have an open topped aquarium then before you get these fish you need to get a hood. Zebra danios are notorious jumpers, and will make frequent bids for freedom by jumping through whatever gap they can get through. Do not be surprised to find that if your hood has large gaps for cables and air hoses that your danios have miraculously managed to get through. There are few fish more tenacious when it comes to escaping their tank to the daylight in the sky than the zebra danio. Taping over these holes is the best thing to do, or plugging them with sponges also works.
Feeding a zebra danio is incredibly easy. They will try to eat practically anything floating and mouth-sized in your tank. They are also likely to pick the snails from your window, but they will never eat them. They will eat flake foods from the surface greedily, and their diet should be supplemented with live foods like bloodworms, white mosquito larvae, water fleas and artemia. Frozen foods will also not be a problem, but freeze dried foods will lack the sufficient nutrition that such an active fish will require.
Zebra danios, while being fairly hardy fish, are prone to have bleeding or ulceration of the gills if their aquarium contains even slight traces of ammonia. This is easily cured with regular water changes, but if it is persistent then it can be a sign that the water you use in re-filling your tank may contain traces of ammonia, iron or phosphates. A good test kit will be required to prove this, and can usually be quickly rectified with ammonia absorbent stones or water conditioner. Both of these things are readily available at your local fish store. If such a problem persists, then you should move the affected fish to a hospital tank and treat with vitamin enriched flake foods and an anti bacterial medication to ensure that the wounded areas do not become infected.
When a zebra danio is nearing the end of its typically two-year lifespan, there will be a moderate to severe curvature of the spine. This is occasionally confused with fish tuberculosis, a disease that can be passed on to humans. If your fish are young and exhibit this particular trait, then you should take the highest precaution in diagnosing the cause. Remember though that stress will often be responsible for the reduction of the life of a fish, and that a zebra danio that experienced a high level of stress as an immature fish may have its life expectance reduced to no more than nine months. Zebra danios are not prone to any particular disease, and because of their active nature they are seldom affected by ich, due to the fact that they will brush off the fungus in their everyday activity of passing by stones or plants in your tank. One thing to look out for is gill flukes. If you spot your zebra danios rubbing themselves along the substrate of your tank, then you will probably need to medicate the tank with an anti parasitic medication.
Knowing that zebra danios need to be kept in schools, preferably away from fish with fancy tails or fins, you can expect to have absolutely not problem with the fish in a community tank. Their nature and liveliness is guaranteed to bring a spark of life into your community, and their playfulness will surely keep you highly entertained. God Bless and good luck.

[hungryhound]

You need to post a link for that as it not your work.

GOod information on behavior, but not sure what advise you are trying to give with that.

[Migforce]

Hi all,

I am a brand new tank owner and need a little help please. I'm concerned for the life of one of my zebra danios! I set up my 20G tank 4 days ago and added 3 zebra danios and 2 buenos aires tetras. Two of the danios keep chasing and nipping at the third. I thought it was just normal aggression that would work itself out, but this morning I noticed the poor fellow hanging out at the bottom of the tank at feeding time.

Am I being paranoid? Is there anything I can do? I thought of maybe adding more danios, having read that schooling might bring down the aggression, but I'm worried that a) he might end up with 4 fish picking on him instead of 2; or b) i'll do more harm to the tank and fish overall by adding more fish at this point. According to my last ammonia test, I'm somewhere between 0 and 0.25ppm. I can't separate him because I don't have another tank in which to put him.

Any advice would be greatly appreciated!

Thanks!
Melissa
I currently have 8 zebras in my tank. A couple of bigger fish used to chase one of the fish around and after a while it also began to hang around the bottom of the tank. The good news that after a couple of weeks the problem seemed to stop and it had rejoined the rest of the school. Just like you at first I feared that that little guy was a gonner, but he seemed to have recovered nicely and is one of the first at the top at feeding time. In fact while he lived on the bottom I guess he learned that some of the food sinks and now does a great job of chasing down sinking flakes.

[gm72]

Chain, Hungry is right. Plaguerizing work is not acceptable. In the future please post a link to the information you wish to share so that the original author receives the credit.

Madly, since you chose to go with a fishy cycle vs. a fishless cycle there is not much that you can do. Adding more fish will add to the toxicity of the water by introducing more ammonia. Your bacteria culture is not mature enough yet. Wait it out, keep an eye on your water parameters. Make sure to read up as much as you can about the nitrogen cycle so you know what to expect. The free aquarium Ebook on this site from the menu on your left is a great place to start your research.

[madly99]

Thanks, all.

I am holding out hope, but the little one was hiding behind a plant in a corner of the tank today when I got home. I practically dumped the food on his head and he ignored it. We'll see what happens in the morning.

I have to say, though, in reading through this forum today, I was surprised to read your easy description of the fishless cycle. I wish I'd seen it before. There really is A LOT of conflicting info out there. I did a lot of reading on fishkeeping and the nitrogen cycle but most everywhere else that I've seen describes fishless cycling as too complicated or makes it sound like you're trying to take a cheap short cut, and recommends just starting with fish.

[gm72]

Ahhh, and that is a large problem with fishkeeping. SO much misinformation. Fishless cycling can be a little scary, only because you will wonder if you'll royally screw it up. I was very leery when I did my first fishless cycle, but when I was totally cycled in about 2 weeks and was able to add most of my stocking at one time I was convinced. Glad you found us here!

[RobbieG]

I remember when I first read it - I was like "they want me to put WHAT in my tank" I thought you were all crazy.:ezpi_wink1:

Now I know better -and wouldn't start off a new tank any other way.

[gm72]

LOL! We ARE all crazy! :28:

[RobbieG]

Didn't actually say you weren't:ezpi_wink1:

[gm72]

A[Only Registered Users Can See Links.] okay, I see how it is! You thought we were all crazy and here we just went ahead and confirmed it! :thumb: Guilty as charged!

ANYWAY, Madly, I think just make sure your fish have plenty of places to which they can retreat. Make sure you don't overfeed in an effort to try the injured guy to eat. Stay on top of your water parameters, and keep us posted!

[madly99]

Thanks, GM! You may be on to something with the retreating bit. The lights went out in the tank and now he's out from behind the plant. I can't tell where he is, though 'cause they all look the same in the dark...

I admit, I did try to force another flake his way earlier on, but he ignored it and Pepe from Buenos Aires snapped it up.

With regard to fish-induced insanity, I have noticed I am getting more strange looks since I started talking about my fish. Makes me wonder what came first, though, madness or fish, chicken or egg... :)

[madly99]

Sad ending with a strange twist - there was indeed a lifeless fish body stuck behind the knob of my heater this morning. :( However, whether or not it was poor little Chris is unknown because one of the other remaining Danios (they were both named Jeff) is missing!

I looked EVERYWHERE - in the plants, on the floor, and in every corner of the tank - only one Jeff. I am assuming the tetras ate him post mortem? They were looking a little guilty. And I imagine the only reason the other one didn't get eaten was because he was behind the heater knob - maybe they didn't see him.

I've been feeding pretty sparsely - only what they can eat in a minute or so, especially because the tetras have also been munching on my plant - but could they be starving?

The last Jeff wasn't eating much today. My ammonia is still under 0.25ppm. Maybe I just had a bad batch of danios?

[hungryhound]

I would check and double check for the missing fish. Including the floor. I had a rainbow fish go missing once and assumed he was eaten. It turned out that he had died in a decoration and a couple days later his decaying body caused my water parameters to crash and I lost half of my tank.

Sorry to hear about your loss.

[gm72]

...and triple check after that. Indeed fish can hide in the darnedest of places.