Zebra Danio Stats
Minimum Tank Size: 5 Gallon (10 Gallon Recommended)
Care Level: Very Easy
Water Conditions: pH 6.5-7.2 and Soft to Medium Hard
Temperature: 65-77 °F (18-25 °C)
Maximum Size: 2.5 inches (6 cm)
The zebra danio (Danio rerio) is one of the most iconic fish in the aquarium hobby, and many people have owned this interesting fish at some point in their lives.
In addition to their attractive coloring and stripes, the zebra danio has a well-founded reputation for being a playful and curious fish and makes an excellent addition to almost any community fish tank.
They were originally found in the streams of India, Pakistan and several bordering countries, but have since spread as an invasive species in several US states. In the wild, they can be found in everything from fast flowing streams, to stagnant rice fields. But their preferred habitat is usually water with a moderate amount of current.
While many of the original zebra danios in the fish trade were wild-caught, nearly all the ones available now have been breed in captivity on fish farms. Because of this, they are adapted to a wide variety of water types, and if given enough time to adapt, will thrive in most home aquariums.
Zebra danios stay relatively small in the home aquarium, and most will only grow to around 2 inches (5cm) in length. With that being said, some have been known to reach sizes of 2.5 inches (6cm) and there have been reports of even larger ones. They also tend to be a short-lived fish, and most will only live two to three years in a home aquarium, though it’s not unheard of for some to live as long as four or even five years.
Housing
People who has ever kept zebra danios, will often swear that these fish have a touch of ADHD. They are constantly zooming around their aquarium, and because of this, should be provided with the largest aquarium possible – or at least the largest one that you can fit into your budget.
While they can survive in a 10-gallon (37 litre) aquarium, they tend to only really thrive in larger aquarium. Since they are a schooling fish, they need to be kept in groups of at least five, and five danios can quickly become cramped in a 10-gallon (37 litre) aquarium. Any zebra danios that aren’t kept in a school, will often become stressed and may begin to display aggressive behavior towards other fish in the aquarium. However, once their numbers are brought up so that there are at last five of them, most of the aggressive behavior will disappear.
Zebra danios are not a demanding fish when it comes to filtration and any HOB (hang-on-back) filter or sponge filter will usually suffice. HOB filters are usually the best choice, since they not only provide excellent filtration, but they also keep the danios occupied for hours playing in the filter’s current or making vain attempts to jump up into the filter discharge.
I would strongly recommend choosing an Aquaclear Power Filter for a zebra danio tank. This filter combines excellent filtration with a durable design, and it will keep your tank sparkling clear for years to come. You can also read the Aquarium Tidings Aquaclear Filter Review here.
It should really come as no surprise, that a fish that enjoys jumping up into the filter outflow, also enjoys trying to jump out of their fish tank. So, to avoid any untimely fish deaths, any tanks containing zebra danios should always be covered. Barring a cover, the water level should be lowered to make it more difficult for the fish to jump out.
Feeding
Zebra danios are not what you would call fussy eaters and will eat nearly anything that you offer them. In the wild they tend to mainly feed on small crustaceans, insects, worms and algae. This diet should be reproduced as closely as possible in the home aquarium, and this can be accomplished through feeding them a high-quality flake food, and occasional feedings of live or frozen foods. I personally use Hikari Micro Wafers, and my fish love it.
But when it comes to live foods, there are few fish that enjoy regular feedings of live food more than zebra danios. They will greedily accept wingless fruit flies, blackworms, bloodworms, brine shrimp and daphnia. If you can’t provide live foods, then they can be provided with frozen bloodworms, daphnia, blackworms and brine shrimp.
Breeding
The zebra danio has a reputation as one of the easiest fish to breed in the hobby, and they can be a great way for a beginner to experience breeding fish for the first time.
Like many other fish, zebra danios first must be conditioned to trigger their mating behavior. The first step in breeding them should always be to separate the sexes into their own tanks. The females can be identified by their plump bodies and rounded bellies, while the males tend to have more streamlined and narrow bodies.
After the sexes have been placed in separate tanks, they should be fed live food for at least a week. If live food isn’t available, a high quality frozen food can be substituted. Over the course of a week, the female will begin to plump up visibly, as they begin to swell with eggs.
While the fish are being conditioned, a special breeding tank should be set up. It should be fully cycled and should only be filled with a few inches of treated water, with river rocks or marbles lining the bottom. The rocks or marbles are integral to the breeding process since it allows the eggs to fall between them – and out of the reach of the hungry parents.
After the fish have finished being conditioned, they can be introduced into the breeding tank, and spawning will normally occur the next day. After spawning, the females will be noticeably thinner, and if they haven’t spawned after a day, they should be moved back into their separate tanks to begin the process over again.
When it comes to parental care, zebra danios are not exactly the model parents of the fish world. They should be removed immediately from the breeding tank after they have spawned, as they are more than happy to eat every egg that they can find. Therefore, it’s important to use the marble setup since it’s unlikely any eggs will survive without it.
Within 48 hours, the eggs will begin to hatch, and the newborn fry can be fed with infusoria, baby brine shrimp or any of the commercial fry foods. While it takes a bit more effort and planning, most aquarists prefer to use newly hatched brine shrimp.
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Dave bullock says
I’ve got a zebra danio that’s gone very big around the belly and it’s belly is red like a boil is it I’ll or could she be ready for breeding
Robert Brand says
That sounds like your fish may have dropsy, which can be tough to cure. Zebra danios may become more plump when laden with eggs, but it shouldn’t look like that. If it is dropsy, the best bet is to immediately remove it to a hospital tank, so that it doesn’t spread. The hospital tank should have one teaspoon of aquarium salt per gallon, and the fish should be fed high quality live or frozen foods while treating it with antibiotics. The chances for recovery aren’t great, but sometimes you get lucky.
To make sure it’s dropsy, you can send me a picture to my e-mail at aquariumtidings@gmail.com. Once I see it, I should be able to confirm that it’s dropsy.
Laura says
My zebra danio looks very thin with an unusual arch on this tail, I’m just worried he might die. I have a 1 gallon glofish tank with a cleaner fish and another glofish. What do you recommend?
Robert Brand says
I would recommend getting a larger tank. It’s almost impossible to keep a 1 gallon tank clean, even if you’re changing the water on a daily basis. This is especially true if you’re cleaner fish is a pleco, since they are pooping machines and absolutely kill small tank water quality. I would recommend at least a 5 gallon, though a 10 gallon would be a much better choice.
The tank probably has ammonia and nitrites building up in it, which is probably making your danio sick. Once you upgrade to a larger tank, your fish should hopefully start to recover. Make sure to use your current filter on the new tank in conjunction with whatever new filter you pick up, since it will take some time for beneficial bacteria to build up on the new filter.
If you can’t afford a new tank, I would start doing at least two water changes a week while you save up for a new one. I hope this helps.
Addz says
Yes you definitely need a bigger tank! Danios should never be kept in groups smaller than five, in a tank smaller than 5 gallons. You’ll need to upgrade or else your fish will probably not survive much longer ????
Rowena Ravenclaw says
Hi, I have a long-fin danio whose belly is kind of plump. I’ve checked and I’m fairly sure it’s a male. He’s eating and swimming normally and there are no protruding scales or bumps or anything like that on his body, But I’m worried that he’s sick or something. Please help!
Robert Brand says
Plump generally isn’t an issue if there are no other symptoms of bloat or illness. It is likely either eggs and it’s a female or you might want to try and change up the diet a little bit. I’d try feeding it blanched and shelled peas to begin with.
Destinee Tucker says
I was told that room temp tap water was fine. Is that ok? I can get drops if needed tho. I can’t afford a filter . How often do you feed them ?
Robert Brand says
Room water temperature is fine, but you absolutely have to get the water conditioner. Chlorine will kill of any of the beneficial bacteria that exists in the tank that help to process waste.
As for a filter, unless you plan to have a heavily planted tank, you will probably just kill your fish. A filter is absolutely necessary, and many are really quite cheap. A sponge filter is a great filter, and with the airline, filter and air pump, you can usually get one for under 20 dollars.
Feeding can be done once a day, or twice a day in smaller feedings.
Sharon says
Hi.
I have a few Zebra Daino fish in my tank. Just 2 of mine have problems. One of them has a bent tail and the other one has a zigzag bent by its tail. I don’t know if its because it tried squeezing though something in the tank and caused that. Or it just happened.
So I’m having difficulty telling if its pregnant or just injured.
Robert Brand says
It sounds like it might be fish tuberculosis. If you can, you should quarantine the fish and use an antibiotic on it. If it spreads to the entire tank, then it must be emptied and sterilized before adding more fish.
Anonymous says
At the bottom of my tank there are little balls. Kinda fuzzy and yellowish. I don’t know if they are eggs or not. My emerald green Cory catfish and my zebra danios have not yet noticed them and I don’t have any type of breeding setup and haven’t conditioned my fish. Is there anyway that these could be eggs? What should I do!??
Robert Brand says
They sound like eggs that have become infested with fungus. Either they were never fertilized, or they just went bad for a variety of reasons. My bet would be that they were from your cory catfish, and not from your zebra danios.
Anonymous says
I had only had my Cory catfish for an hour when I saw the eggs. I’m sorry that I didn’t mention that before.
Robert Brand says
Do you have snails at all? It definitely sounds like eggs that have grown fungus though. It’s rare for any eggs to survive that long in a zebra danio tank. They are notorious for eating their own eggs, and while I’ve kept danios from the very beginning, I don’t think I’ve ever seen any eggs in their tank.
Fish Guy says
Zebra Danio I’ve had it for about 2 weeks and it’s lost most of the color and it has a small nip on the back Finn I have it all on its own I was told that this particular species will be fine on its own but it appears that I was lied to. Let me know if you know what’s going on my dear he is stressed tell me if I’m right or wrong?
Robert Brand says
First of all, what are the water conditions like? Was the tank full cycled before adding it? If you don’t have a testing kit, most stores will test the water for free for you.
Also, what sort of fish are it kept with? Does it have anything looking like fungus on it, or any small white dots?
Let me know, and then hopefully I can help.
Maddy says
i have three zebra danios in a community 10 gallon tank and two of my zebra danios are really fat. they cant swim that well any more. i am pretty sure the third is a male. i put all three in a intank nursery today and both of the fat ones would rest on the bottom. not laying on their side but perched on their bellies. are they pregnant? or am i doing something wrong
Robert Brand says
They sound ill, and they may possibly have bloat. When a female becomes swollen with eggs, it shouldn’t change its behavior in any majorly noticeable way. Are the bellies very swollen? Are the scales sticking up at all?
I would immediately start with a large water change on their tank (25% of the water or so). Make sure that the water is treated to remove any chlorine, and then I would try to feed them some high quality frozen foods like bloodworms.
If the bellies are very swollen, you may want to consider some antibiotics for them, though I should warn you that the recovery rate from bloat is very low.
Cecile says
Hi 🙂
About a month ago I adopted 6 zebra danios off a friend who wasn’t looking after them at all! When I took them home they were pale and didn’t swim around much, I didn’t even think they would survive but they have and they seem much happier! As of recently though, 1 of them (who I think is a female after reading this post) seems to be chasing off all of the other fish away when they go near it, more then usual. I’m not trying to breed them at all, is there a chance that she has or has had babies? If not is this normal behavior? They all Chase each other around sometimes but this one stand out from the rest coz it’s a bit more rougher. Based on your post I THINK I have 5 boys and 1 girl. I’ve never owned fish before, I’m loving them heaps and find myself sitting there and watching them for ages lol I just want to make sure that I’m not doing anything wrong 🙂 they are in a 10 gallon tank with a sponge filter and there is a male fighting fish living with them too 🙂
Robert Brand says
That’s good that you adopted the fish off your friend and gave them a good home. Once zebra danios become more comfortable in their new home, they will often establish small territories in their tank. They also generally have a pecking order, so chasing is also quite normal for them. It sounds like you’re doing great so far with them.
Just keep an eye on the fighting fish though. Zebra danios will sometimes nip their fins, and if you start seeing damage, you may need to rehome it.
brandi says
Hey robert
I recently bought a 55 gallon that came with 3 zebra danios in it. They are huge 2.5″ to 3″ and I am not sure of the age. I noticed several small fry inside my tank I was able to remove 7 of them.. 6 look ok. If I was to try and raise them what would be the best way. Right now they are in a betta sized tank at room temp since I wasn’t expecting any new additions. They are lucky as I have an albino rainbow shark, upside down catfish and a black ghost knife in the tank that they managed to escape from. Any advice or tips would really help me.
Robert Brand says
That’s great that you found some fry. You definitely need to move them to a larger tank though. Fry are very sensitive to water conditions, and they won’t do well in a betta tank.
I would recommend at least a 5 gallon tank, with a sponge filter on it. I would also include lots of fast growing plants like hornwort in the tank, since it won’t be cycled when they enter the tank. Once they’re in the tank, they can be fed crushed up flake food, or any of the small live foods like microworms of baby brine shrimp if you don’t mind putting in the extra work.
If you can’t set up another tank, I would recommend using a breeding net in your main tank. I’m not the biggest fan of breeding nets, but in this situation it would be far superior to the betta tank. In a tank that small, there’s very little chance that ever a hardy fish like zebra danios will survive.
I hope this helps.
p.s As your ghost knife grows, all of your fish will start to disappear.
brandi says
Ok great I actually have an empty 5 gallon and a few extra live plants currently. I will head to the aquarium store for some food for the fry. Right now my ghost knife is smaller then the danios but at what point should I separate them?
Robert Brand says
In my experience they start to become dangerous to other fish when they reach around 4-5 inches in length. For safety sake, I would recommend relocating it at the point. They grow very large though, and an average one can easily reach 12-13 inches in the home aquarium. So it will need a big tank on its own.
Vicki says
I have 50 or so neon Danios. Apparently one of the adults laid eggs right before we switched tanks. The old tank was not emptied right away, and three days later it was swarming with fry. There were close to one hundred at first. They are now almost two months old. Our biggest tank is 25 gallons. How many will survive in there? What do I feed them now that they are bigger? They have been eating crushed shrimp pellets, but the tank gets nasty fast.
Robert Brand says
They should be fine with what you’re feeding them, though they would appreciate frozen foods now and then. Once they’re a bit larger, you can start feeding them frozen blood worms, daphnia and brine shrimp.
As for how many will survive, all I can say is that danios are incredibly resilient. They can survive in terrible conditions, which will cause problems for you later down the line. If you keep up with water changes, and the tank doesn’t crash completely, you could end up with most of them alive well into adulthood. However, they will probably be unhealthy, with damage to their gills from ammonia and they will also probably be stunted. I would give a large number of them away so that the ones you keep will remain healthy.
Vicki says
Thank you for the info! We have been trying to give them away, but nobody wants them. I know we can’t sell them, but will a fish store take them off our hands? Otherwise we’ll be searching for a large enough tank so the survivors stay happy and healthy!
Robert Brand says
Most fish stores will either take them for store credit, or will just simply take them off your hands for no money. The caveat is that they have to be at least half an inch (1.5 cm) before most stores will take them. Another great resource are regional fish forums. If you look, most major cities have a fish forum that usually have a for sale section.
I hope you find a home for them.
Vicki says
Also, what is a good bottom feeder for them? I’m afraid our Cory fish will eat them, and the snail doesn’t eat enough.
Robert Brand says
The majority of fish will eat zebra danio fry if given the chance. And what do you want the bottom feeder for? If you’re looking for a clean up crew, I use Malaysian trumpet snails in most of my aquariums. They’re relatively attractive, and consume all the uneaten food and a fair bit of algae.
Tok says
Actually it is better if you use ghost shrimps. I use them and they are doing a good job
Zipporah says
What do you recamend gravel or sand for them.
Robert Brand says
It all depends. I run so many tanks I mostly use play sand, since it’s less than 1/10th the price of gravel. But I will say gravel tends to be easier to clean and keep on top of. If price isn’t an issue, I’d probably recommend gravel for a small zebra danio tank.
Tracy westall says
Hi,I have 2 danios,one female n one male.They share a tank with 2 guppies which have recently had babies.Ive noticed that my female Danio has a white lump growing off her mouth and is very bloated,could you please tell me what I can do to help as she’s not as lively as the male and tends to sit at the bottom of the tank when usually they both chase each other around the tank and seem quite lively x
Robert Brand says
It sounds almost like your fish has two things wrong with it. The mouth problem sounds like columnaris, and the bloating sounds like dropsy. I would immediately isolate the fish in another tank if possible, and try feeding it antibiotic food. The prognosis usually is not very good for this sort of affliction though, and it’s also high contagious. It’s important to get it away from your healthy fish as soon as possible.
vicki Beckman says
I have a neon Danio work a very strange deformity. I cannot even begin to describe it. Is there a way I can share a picture of him and maybe someone could tell me what is wrong with him?
vicki Beckman says
“with” not “work” a very strange deformity…
Robert Brand says
You can e-mail it to me admin@aquariumtidings.com
megan says
i’m 15 from wales (uk) and a complete novis. my local fish store recently shut down and i was wandering if you could help me make sure i’m doing everything right.
my my tank is 10” tall, 8” wide and 24”long. inside it I have a male and a female zebra Danio, a female leopard Danio, an albino leopard Danio, 5 Odessa bards, a zebra nerite snail, a ramshorn snail, one more snail I’m not quite sure what it is, and a batch of adhesive eggs(any idea which they might be from?).
in my tank I used gravel, a lot stone’s and shell’s(I found them at the beach and boiled them for 2 hours), marbles, three medium sized plastic plants, a small fake bark tube with loads of hole’s in it and a really small live plant. my filter is a sponge filter with a nozzle that project’s water to create a small current and an air tube. my light gives out “5VDC of light”
there are no lumps on my fish, or whiter spots or upturned scales. there colours are bright and they cotinualy chase each other round the tank. I change my water once a week ( after declaurentating the new water), and feed them with tropical flakes as well or sometimes freeze dried blood worm or live brine shimp.
is there anything else I should be doing or that you would recommend?
Robert Brand says
Nerite snails are notorious for plastering aquariums with eggs, and that’s the most likely culprit, though they won’t hatch in freshwater.
As for the rest, you’re doing really well – better than the majority of people do. Just keep up the good work, and maybe try to offer your fish the occasional veggie, and you should do great.
megan says
that’s a relief!
the eggs didn’t hatch and have been eaten now, but after your message I wasn’t surprised.
one of my fish did develop a pale patch on his head, but I removed him to separate tank that, at my nan’s suggestion, had aquarium salt in it. I feed him on freeze-dried blood worm for a week and a half and the patch faded away and his markings brightened up so I but him back in the main tank. he’s only gotten better since, even started standing his ground a bit more around the other fish (he’s the smallest in the tank).
did I do the right thing?
+ do you mean veggie as in broccoli and carrot’s or veggie as in some special tank stuff?
Robert Brand says
It sounds like you did the right thing. Good food, and a space to recover always helps.
As for veggies, I find zucchini is among the best, but I stay away from hard ones like carrots. Always make sure to lightly blanch the veggies, and wash them thoroughly.
megan says
thanks so much Mathew, for the help. I wish there were more people like you around. helpful, I mean people who really know what their talking about, who’ve learned through experience not been handed the word professional on a certificate.
Robert Brand says
I’m always glad to help people out there. Fish are amazing, but they can be difficult to keep at times. I know, since I made just about every mistake possible when I started. lol
sam says
Why is It that so many danios I see have spine deformities? (Like a humped back, a “s” curve, etc) or develop them as they age? I once had a danio for 4 years who mysteriously developed a crooked spine. Also, most my fish (danio, guppies, bettas and an angelfish) develop extended/protruding fin rays (esp. On the cadual fin) which naturally snap off after a few days, every month or so. Is this normal? None of my other fish have ever had scoliosis (deformity of the spine) just zebra danios and leopard danios.
Robert Brand says
The spinal deformities are pretty common among danios, especially as they age. It’s mainly caused by inbreeding, though there can be other causes. Do they have any other symptoms, or just the bent spines?
However, if you begin to notice lesions, loss of scales, or loss of color in your fish, be extremely careful, and do not put your bare hands in the aquarium. Also, do not start the suction with your mouth, and carefully wash up after touching anything in the aquarium. Any of those symptoms means it could be fish tuberculosis and you do not want to catch that. It can cause major problems if it infects your skin, and if you suspects it’s fish tuberculosis, you’d probably be best euthanizing all of the infected fish.
As for the fins snapping off, I’ve never heard of anything like that before. Are you sure they don’t have fin rot, where they are slowly rotting away? How do they ‘snap’ off?
Mason Lemont says
Hi I have 2 zebra danios, one male and one female. The female I thought was going to have babies cus her stomach was fairly big but about a day later the male got the same size.
Whats happening?
PS. the female Iv had for about two years, and the male about two weeks
Robert Brand says
I apologize for the delay in getting back to you, but large stomachs is usually as sign of an infection. There is usually no way to treat bloat, but you can try antibiotics. I will say by the time the disease is showing in smaller fish, there is usually massive internal damage, and there is no hope of saving them. But I wish you all the luck if you try to treat them.
Lauren says
I think I have 2 female and 2 male Zabra Danio’s. The 2 females look rather plump. I put the fattest one and a male that had been chasing her around for a few days, into a separate tank with a heater up to 25C and turned the filter off as that’s what I had researched. Left them overnight and nothing had happened by this morning. Is she not fully ready yet or am I doing something wrong?
Robert Brand says
The problem with danios is that they will happily eat all of their eggs for spawning. That’s why most breeding guides recommend putting them in a tank with marbles in the bottom. That way they can’t reach the eggs after spawning,and the eggs will be easily visible. It’s quite possible something did happen, but all of the eggs were consumed by the time you saw them in the morning.
Also, I often keep them separate before breeding, and that way you know they won’t have spawned prior to putting them in the tank. If nothing happens then, you can take them out again, condition them with good food, and try again in a few days.
emilyeller2 says
I have recently bought an 8 gallon tank and after cycling the tank for around a month I bought 2 danios and then week later bought an additional 2. The aquarium that I bought them from indicated that that the tank size I had would be perfect for them but now I’m concerned that it’s too small and might actually be cruel. I’m reluctant to re-purchase everything in order to cycle a new larger tank. Is the 8 gallon tank I have now suitable for 4 zebra danios? What do you suggest?
Robert Brand says
I think you’ll be alright, as long as you keep on top of water changes, and have a good filter on the tank. You might want to add a few small plants too, as that will help keep the tank clean. Eight gallons is right on the edge of what is appropriate, and ten would probably be better. But you’re not overstocked, and you seem like a good aquarist since you’re worried about them, so with a bit of hard work they should be fine.
david says
I have 2 flow zebra danios and a dragon fish in a 10 gallon tank is that a smart idea
Robert Brand says
Do you mean a dragon goby, or an arrowana?
Rada M says
Hi, I have a question for you, hope you can help, I have bought 5 Danios about a month ago, and am not sure about their sexes, some have plumped up while two are slimmer, what I need to know is if I only have females in the tank, and they’re filled with eggs, will they die if they don’t have a male to fertilize their eggs? Like, will they release the eggs anyway without a male or would they be fine even if they don’t release the eggs. They are in a tank by themselves, heavily planted, air stone and air pump filtration, and I do the cleaning about once or twice a week since the tank is only 4 gallons.
Robert Brand says
The majority of females will reabsorb their eggs if there are no males around. But with five fish like that, the odds are that you have at least one male in the tank, so I wouldn’t worry about the eggs becoming egg bound. And treating an egg bound fish is extremely tricky, and only something I’ve ever bothered to do with mature koi.
Fish lover says
Hi i just wanted to know if i am doing anything wrong.
I have a 10 gallon tank with 11 danios. 1 leopard danio and 2 neon danios and 8 zebra danios. I just bought them today! So excited! Anyways i fed them pellets today i fed them very little as i thought that the fish shop might have already fed them. I just bought freeze dried bloodworms from a pet shop. I have a few questions:
Do I feed them the freeze dried bloodworms everyday or pellets everyday and occasionally pellets?
Will my danios get cramped?
I have no sand or gravel or aquatic plants just a bare tank with a sponge filter and an aeration. Is it enough or do I need to get accessories?
How often do i leave the lights on?
Is it compulsory to get live food occasionally? Or is the freeze dried blood worms enough?
Thanks for reading ! I hope to get a reply soon!
Fish lover says
And occasionally freeze dried blood worms not pellets XD
Robert Brand says
First of all, your tank is very overstocked, and you’re probably going to run into water issues sooner, rather than later. A good rule of thumb is one inch of fish, for every one gallon of water. And since danios grow to over two inches in length, the maximum you’d want in a tank that size is five fish (maybe six to make a school if you’re on top of water changes).
You should feed them the pellets once a day, but only as much as they can consume in around three minutes. The worms can be fed about once a week as a treat, and make sure you hydrate them first in a small cup of tank water before you feed them to your fish.
I would also recommend adding gravel to the tank, and some accessories, or live plants for the fish to hide behind. It allows them to escape from aggressive fish, while the gravel gives additional space for beneficial bacteria to colonize the tank. If you’re not familiar with beneficial bacteria, they’re the ones that break down the fish waste into the less harmful nitrates (which are then removed in water changes).
And live food isn’t compulsory, but fish really love it. So treat your fish if you can. 🙂
Marcus Gallagher says
I have a quick question. I started a new tank recently and put in two small danio (they must be very young as they are smaller than an inch) – they aren’t zebra danio, not sure what type they are but they are a ginger/orange colour. I was wondering will they shoal with any danio if i added a couple zebra danio? Can they also breed with different danio or only their own type?
Robert Brand says
It sounds like you have gold danios there, and if you do, they’re just colour variants of zebra danios. So they will happily school together, and will interbreed, though you might get some strange looking fry.
Richard Edward says
Hi a little help please my zebra danios laid eggs and its abut 4 days I can c tiny brown coloured baby fishes inside the egg and it was also moving nicely until the second day but afterwards its not moving inside the egg and no hatching also I’m sure they r babies but don’t no y they r not moving please helo
Robert Brand says
The usually take a little while to hatch, but it’s not uncommon for something to happen to the eggs. Have they eggs changed colour? Any sign of fungus on them? Did you remove the parents, and is it in a separate tank?
Hippo says
I have 5 zebra danios and i was wandering if they enjoy plants and caves in the tank.
Robert Brand says
They definitely will benefit from the addition of live plants, or even high quality fake plants, but they would never really bother with caves. They tend to dwell in the top and middle of that tank, so caves would be wasted on them.
Jason says
My danio has 4 other Fabio’s with it one is older. A 30gallon tank. I notice the one became very bottom heavy and bloated around the belly. I came home today to see that the other danios where constantly chasing it and cramming him into a corner. He also tends to drop very fast when he slows down. I currently moved him to a 2 gallon tank so that he doesn’t get Burt or bullied etc or just incase he has a disease like dropsy or something. Any help would be great
Robert Brand says
Dropsy is incredibly difficult to cure in a small fish like that. Usually, by the time you can see it, there’s significant organ damage. It might be a swim bladder problem though, and you can treat it by feeding it lightly boiled and shelled peas. If that doesn’t work, you can try epsom salt, and it’s usually about half a teaspoon for 10 gallons, so you’d only need to a put a pinch in a small tank like that.
If that doesn’t work, you could then try antibiotic food, but very few small fish will ever recover from bloat. So it’s often not worth putting your fish through that. Hopefully, it’s just a swim bladder issue though.
Johane says
Hi Robert,
I bought 4 Leopard Danios for few months ago & lately one of them became plumped & rounder. She has been like this for about 3 weeks & been chasing & nipping other danios constantly. but she is very active & eating normally.
Assuming that she is gravid, how long can she carry the eggs?
& i have just one extra tank with juvenile Red Cherry & Yellow Shrimps in it (30g, planted, sand substrate, indirect sunlight), can i put the danios in that tank to trigger spawning? or the danios will make a feast out of the shrimps?
Robert Brand says
I don’t have any information on how long they will hold the eggs, but they will normally hold them until something triggers their spawning behavior. It could be a large water change, a slight change in the temperature of the water, or adding live and frozen food to their diet. Sometimes it will just trigger on their own, but you don’t often see a leopard danio remaining gravid for long.
As for the shrimp, the leopard danios will decimate any juvenile or hatchling shrimp in the tank. Usually, the adults will be fine, but anything small enough to fit in a leopard danio’s mouth will be eaten.
Tom says
If i have a 10 gallon tank with some ghost shrimps, two fishes i dont know, an angelfish and 4 zebras as well as one in pink. The tank have gravel as well as lots of shells and stones and have at least 5 differnt fake plants. Im using a sponge filter with a air pump, can you tell me how i can improve it. And what species is that pink zebra like fish. Btw the two other fishes is moving out soon.
Robert Brand says
The pink danio sounds like a GloFish, which is a genetically modified zebra danio.
As for the tank, it sounds like you’ve got a pretty good setup, though it is overcrowded. If you were able to relocate the angelfish and the other two fish, then you should be pretty good for number of fish in the tank. Anyways, angelfish grow way too large for a 10 gallon, and you really want to get it into a 29 gallon for it to be happy.
Pete says
Hi.
I have a new (cycled for a month) 10 gallon tank. Added 6 zebra danios and they seem to be healthy but a couple are slightly aggressive.
1. Am I at stock limit or could i add a couple more fish?
2. If I can add one or two more what could i add? Im worried the danios might Attack a new fish or the whole tank might be cramped for them.
Robert Brand says
You’re pretty well at the limit right now, and even if you could squeeze in another few fish, there are very few that would like to be kept individually, or even in pairs. And it’s normal for zebra danios to be aggressive, but when they are kept in groups like that, it should be spread out pretty evenly. In my experience, they will eventually stake out territories, and it will start to die down.
Pete says
Thanks.
Im happy with the danios but I did want to add a splash of colour with a guppy or something but I realise the limitations of a 10 gallon tank.
Is there anything else I could get like snails or shrimp or a pleco?
Robert Brand says
All of the readily available plecos would grow far too large for you tank. Maybe one of the smaller mystery snails would work, or Japanese trapdoor snails. Nerite snails are stunning, but can difficult to find depending on where you live. But they do come with the added benefit of not being able to reproduce in freshwater, which means they won’t take over the tank.
But now that I think about it, one of the best things to add might be African dwarf frogs. They look great, and are incredibly interesting to watch. Still not a lot of colour though.
Don says
Hi!
There are 11 zebra danios in my 180L tank (and one super red pleco). Nine males and three females. The problem is that few times a day they show very aggressive behaviour towards eachother. It’s not fun to see, to be honest. What could the problem be? (this has been going on for weeks)
Robert Brand says
It’s actually pretty common with zebra danios, and unless they’re doing damage to each other, you don’t need to worry about it. They usually develop a pecking order in their aquarium, and they will put on shows towards the other fish. It usually doesn’t even progress to fin nipping though, and like I said, if they’re not doing any damage, you really don’t need to worry about it.
However, if you want to try to lessen it a little bit, you can make line-of-sight breaks in the tank. This can accomplished through tall plants or ornaments, so there are places in the aquarium where they can’t see each other. Or if they swim away, they are quickly lost from sight. It won’t stop all of the aggression, but it will limit it more.
Don says
It looks like they aren’t doing any damage, so it should be alright then. Still it doesn’t always look nice the amount of violence 😀
What about if I get more females? Sometimes they are chasing the girls, which again can be really violent.
Thank you for your reply and tip!
Robert Brand says
Females may help, but it probably won’t make much of a difference. It’s pretty natural behavior for them, and not always the most peaceful thing to watch. I would go with rearranging your tank, as that would probably have a far greater impact.
Don says
Thank you. I’ve bought new plants and will make some places for them to hide.
Again, thank you for your help. I appreciate it!
Richard Edwards says
hey got some more eggs today of zebrafish but sad to say that it is in a very small bowl that i cant even put a heater is it okay if it is in that bowl or should i changr them
Robert Brand says
It’s always best to do it in a fully cycled, filtered and heated aquarium (though zebrafish do alright at lower temperatures than most other tropical fish). Otherwise, you’ll have a very high mortality rate. Unless you have something else set up, it’s probably best to just leave them where they are.
Richard Edwards says
thnx now they hav hatched and they are staying on the walls
Bryony says
Hi there, I got some danios (one zebra and one leopard) yesterday from a local store here in the UK. I knew nothing about them, went to buy goldfish and the staff at the store said the tank I picked would suit danios more because it’s a small tank. But after carefully reading through all of your advise I’m worried that the tank is too small – 7 litre for 2 fish (with pump and waterfall and a rock/plant decoration and gravel) and also had no idea about the live or frozen food so bought standard flake. Are they going to be ok? Is there any key advise you have – feeling like the store didn’t do their job well! Thanks
Robert Brand says
Unfortuntely, that’s far too small for zebra danios. It will be almost impossible for you to keep the water clean. The only thing you can do now is either really keep on top of water changes and be very careful to not overfeed, or transfer them into a larger aquarium.
And don’t feel too bad about the bad advice – we’ve all been there one time or another.
Leila Wrightson says
Hi. I have 5 zebra fish and one of wich is a female. I can tell she is ready to mate and only set up the tank safely 1 hour ago. How long until I can move her and her mates?
Robert Brand says
You’ll have to wait until the tank is fully cycled. This is especially true if you want to rear the fry in the tank, as nothing will kill fry quicker than an uncycled tank.
Also, it’s best to condition them with high quality food separate from each other for a while, or they may just mate on their own in the tank and you’ll never even know. Once the tank is cycled, you can place the female in it for a while until she looks very plump. Then you could add the male to the tank.
Ellen says
Hi 🙂
I have got a 25 litre tank and currently have 2 danios in it. I was told by the assistant working in my local fish shop that we would be okay adding 2 guppies and some shrimp within a few weeks. Is this information correct? Having read your page I’m worried I’ve been given the wrong information. Will they get on and is the tank big enough for this? If not what would you recommend for a tank this size?
Thanks!
Robert Brand says
I always recommend sticking to a species only fish tank in smaller aquariums. Zebra danios are much happier – and in most cases healthier – when kept in groups of at least six. Also, if they are kept in smaller numbers, they may nip at their tanks mates, and if you have male guppies it could be a major problem.
But in this case, the tank is probably too small even for the non-demanding zebra danios, and anymore than three would make the tank very difficult to maintain. The problem is that there just isn’t enough water and space for the beneficial bacteria to handle all the waste the fish will produce. If you really keep on top of it, it may work, but anything smaller than 37 litres (10 gallons) is very difficult.
You could probably make a go of it with just a handful of male guppies in there, if there is any way to return the zebra danios. Otherwise, I’d recommend upgrading to a larger aquarium if you can afford it.
Mimi says
Hi ??
I recently bought two Danio fish one stripped one which is the female and the white/ gold one which is the male. The problem is my female fish keeps chasing the male around the tank In an almost aggressive manner. I bought a ornament so he can hide from her but he doesn’t go in there. I’m just worried that she will eventually start to stress him out. I don’t know what else to do ?
Robert Brand says
You often find that when you keep small groups together. Can you buy four zebra danios to bring them up to the minimum recommended group size of six? Otherwise, it will probably continue. However, you can add tall plants to break up the line of sight which works sometimes.
Mimi says
Thank you for you quick response Robert.
If I was to buy more Danio would it mean buying a bigger fish tank? I only have a 10L tank and I read that these fish need plenty of room to swim. I was thinking of buying one more female which might help. What do you think?
Robert Brand says
That tank is really too small for the ones you already have. The problem with small tanks is that it is really hard to keep the water clean. It’s really easy for the water quality to go out, and then you usually end up with some sick or dead fish. Large tanks are actually much easier to maintain and if you decide to upgrade someday, I would recommend at least a 10 gallon.
Right now, I wouldn’t add any more fish. If you do upgrade, you’ll probably see less aggression as well.
Zachy says
My zebra danio has jagged scales on top and bottom of his/her body.
Could it possibly be fin nippiping or what?
Robert Brand says
Does it appear bloated as well? Sometimes the scales stick out when the fish have bloat.
Zachy says
Do I have to euthanize it?
Is it a disease? If so, can it be cured?
Please help meeeeee!!!
Beryl says
Can pink danios live with kili in the same tank?
Robert Brand says
What kind of killfish are they?
Beryl says
Abred-striped killifish, just one female.
Beryl says
*red-striped
Robert Brand says
They should be fine living with pink danios, but you need to make sure the red-striped killifish don’t get out competed for the food. They tend to be rather shy fish, and with a boisterous fish like the pink danios, they may dominate the feedings so the killifish don’t get any. Beyond that though, as long as you have a large enough tank for both of them, and you keep the danios in a group of a least six to lower aggression, you shouldn’t have any problems.
Damion says
I have a 20 gallon tank with a good filter set up and have 4 leopard danio’s and 1 zebra danio’s. I know 3 of them get belly’s (females) and the other 2 never have(males). When the females lose there belly I have removed them and the male but I have not had any baby fish appear. What am I doing wrong?
Robert Brand says
Assuming they’re breeding, they usually eat the eggs the instant they are laid. That’s why you need a special breeding setup with marbles so the eggs fall down beyond their reach. Occasionally, a few eggs might not get eaten, but it’s pretty rare.
saikrishna says
can i keep danios with angel fish, gourami and neon tetra . i have a 350gal tank with 4 angel fish , 6 gourami and 50 neon tetra . can i keep pink danios
Robert Brand says
They should be fine in that setup, though angel fish do enjoy eating neons. So as the angel fish grow, you may start to lose some neons to them. But the danios can more than hold their own against any of those fish, and will be quite happy in a tank that size.
saikrishna says
are there any more very hardy fish to keep in the community tank , but i dont want fish like molly, guppy and platy ,i know they are hardy but they give a lot of fry and i cant control that
saikrishna says
are there any other very hardy fish that i can add to my community tank but i dont want fish like platy, guppy and molly as they give a lot of fry and i cant control,
and can i keep a female betta school in my tank
Robert Brand says
There are quite a few hardy fish out there, and female bettas schools work sometimes – though not always. You need at least five, and have to hope they establish a pecking order.
But harlequin rasboras, rosy red minnows, corydoras catfish, and blackskirt tetras are all good choices for you.
Joe says
I have two zebra danios. They looked normal only yesterday but today one looks rather plump. Could it be pregnant? That fast. I had them together for years but recently upgraded from a 10 gal to a 36 gal tank when this happened.
Joe says
I have an intank breeding tank I can put her/them in but I don’t know if its eggs or bloat.
Robert Brand says
It could be eggs, or it could be bloat. But when it’s that fast, something is probably wrong. Are the scales sticking up, so it almost looks like a porcupine? Is it sluggish, and swimming funny?
Joe says
There doesnt seem to be any scales sticking up at all. When she does swim, she seems to swim normally but she has taken to hanging out at the top corner of the aquarium. Kind of out of the way of everyone else
Robert Brand says
It’s probably just eggs then. Keep an eye on her, but she’ll probably scatter them in the aquarium soon.
saikrishna says
hi, do u know of any good plants for a pond, i have papyrus, pothos, lotus and arrowhead plant , i want to add 2 more plants that can survive in very hot conditions like 45-50′ c , fish wont be a problem cause i only have around 150- 200 platy and 50-100 guppy and 2 gourami, & can i keep aquarium plants in a pond ? i did put anubis in the pond and its doing fine but i am not sure of keeping any other plants cause there is no filter and no CO2
Robert Brand says
Many aquarium plants will do fine in aquariums, but you have to make sure they aren’t considered invasive species in your area.
Do you want submerged? Floating? Marginal?
kate lebroc says
i wonder if you could help me, i have two danios and 5 platys in a 200L tank. One of the danios has been staying at the top of the tank, he does occasionally swim around the tank, but not often, he opens and closes his mouth all the time, even when swimming around.
HE IS SMALLER THAN THE OTHER ONE, WHICH DOES TEND TO CHASE HIM AROUND THE TANK A BIT, BUT i AM WORRIED ABOUT HIM STAYING AT THE SURFACE. WATER CONDITIONS ARE FINE BY THE WAY?
Robert Brand says
Usually, that indicates a problem with the water? What is the temperature? Is there a filter or aeration?
And when you say he’s at the top, is it like he’s gasping for air? Or just hanging out near the surface?
kate lebroc says
I have two air stones, plenty of bubbles.. and an external filter, the water is testing fine, he doesnt seem to be gasping, just opening and closing his mouth, which he does all the time, even when he is swimming around, he has always done it since we had a couple of weeks ago.
I have salt in there at the moment, as we had white spot on one platy, none of the other fish have shown signs of it, although i know from reading forums that that doesnt mean they havent got it. it seems to be clearing and the affected fish only has one spot now.
He is a leopard danio, and has pink gills.
Very pale in colour, does this indicate anything?
the temperature is about 25 degrees celsius.
Thanks for your help.
Robert Brand says
Is it flashing or rubbing on anything? Usually, what you’re describing either indicates a parasite, or water problems.
What are the levels when you test the water?
kate lebroc says
i only have ammonia and ph tester at the moment, but the ammonia is on 0 and ph is 7.
I noticed last night he is a bit bloated and his scales are slightly up…i put peas in in case it is constipation, but he didnt eat any of them, he tends to stay away from the other fish, and they were going mad for them, he came down the tank, but wouldnt get too close to them.
I did a 25% water change too just in case.
I have another tank with the filter running, its needs setting up properly, and needs a good clean out, i moved the fish from there last week into the bigger tank,Do you think I should move him into that one?
Is there anything else you could suggest?
kate lebroc says
Oh, and no, he is not rubbing on anything.
He does seem to be more swollen on one side than the other though?
I have read several posts that ask if the fishes back is straight, I do think this one has a slightly curved back, like a small hunch, but i dont really know what that means?
Robert Brand says
Not much at this point, but if it doesn’t resolve, I would consider moving on to antibiotics next.
kate lebroc says
Too late…he died in the night!!:-( I am gutted, what did i do wrong? is there anything else I could do if it happens again?
Could it be an illness that the other fish have already picked up off him?
saikrishna says
i need shallow water and submerged plants in my pond .
dont want Floating plants, i just add water hyacinth to my pond in the summer as it gets very hot as i dont have any filter i have to add it to control the chemistry in the pond but its a takes a lot of work to remove it after summer ends , i plan to keep marginal plants on top of pots , in middle of the pond to give shade so i dont have to use water hyacinth and submerged plants for controling the chemistry in the pond , i heard that marginal plants dont absorb a lot of nitrates from the pond so i need submerged plants,
i need submerged plants that can stay in v high temp , like 40-45*c
Robert Brand says
I honestly don’t know any plants off hand that can survive in water that hot. Most of the ones I know only really grown in in 30ish max temperatures. Also, I’m in Canada, so I’m not terribly familiar with tropical pond plants.
Why is your water so hot? If it’s cooler in the deeper parts, many of the more popular ones like anarcharis or hygrophila polysperma.
saikrishna says
my water is temp is around 35-40 but the out the outside tem is 45, and the pond it 3ft deep
Robert Brand says
Then you should be fine with most of the regular plants. Sorry, I should have asked, but what country are you in?
saikrishna says
india , south india
Joanne says
Hi Robert, about a month and a half ago I bought 3 zebra danios to add to my community tank, one of them being a longfin. A week later I got 2 leopard danios. All of the danios except the longfin seem to be female as their bodies are rounder, while the longfin is very streamline. I fed them live mosquito larvae, flake food, and boiled peas. They’re very greedy fish so it’s hard for me to tell if they have eggs, or if I’m just feeding them too much. If I was overfeeding I would expect the longfin to get fat too but he looks fine. But if the others are female shouldn’t they get even bigger with eggs if I’m feeding high quality foods? Or maybe they scatter eggs here and there without me noticing. I’ve noticed the two normal zebras were doing like a head to toe stand-off thing, which I thought was typical behaviour of males. I want to separate males from females into conditioning tanks, but despite feeding good foods, I still can’t tell the difference. One moment I’ll think I have 4 females and one male based on appearances, then I’ll think I have 5 males based on behaviour. They have plenty of room to swim and chase eachother but don’t get overly aggressive. I really want to get a few more either zebras or leopards but not sure whether i need more females or males! What do you think?
Robert Brand says
They often scatter eggs in the aquarium and then proceed to eat them all. A good trick for telling males and females apart is to look at them from above. It’s easier to tell which fish are plumper from that angle. But usually you can tell from the belly underneath. Even if the males are getting fat, it won’t be as round as the females belly.
There’s lot of little other ways to tell, but they’re quite difficult in a real life situation. Hopefully this helps.
Joanne says
Thanks for your reply. I now have 9 danios in total, including 3 new delicate little longfins. The two leopard short fins are the biggest danios i have and have gotten the roundest and one of them became quite aggressive – didn’t hurt anyone, just kept scaring them behind plants. As she’s quite big now I’ve put her in a breeding tank yesterday with a male zebra danio. Here and there they play together, chasing each other and flaring fins while encircling each other, but for the most part the female just chases the male and he swims away. Is there any reason why they wouldn’t spawn? I put them in the breeding tank together on the same day, I’m thinking that could be why so I may separate them for a few days. Is it possible the male also isnt interested and I should add my male longfin? Also my 2 female short fin zebras seem to have a few small scratches on their backs, and the leopards do pick on them the most. Do fish leave scratches though? Or could this be something else? No one has had any fins nipped so for the most part the bullying isn’t too bad, I feel like the females just get aggressive when they’re filled with roe, so I wouldnt mind some fry babies but for the most part I want my fish to lay eggs and settle down before I put them all back together in a fresh tank to reestablish their pecking order… Any suggestions? And sorry but this is still bugging me, but do both female and male danios flare their fins at each other side by side or head to toe? And if so, do females do it to other females and males to other males, or males to females only? Because if I’m correct with the sexes of my fish, it appears every fish has flared its fins at some point. The female leopards do it to eachother and the zebra females do it to eachother, and the longfin male does it to his fave zebra. With the male and female it appears the male is courting her, but with all the females it’s more like a comparison of who’s better of the two. Im just unsure as with my white clouds, only the males really flare their fins… Does this sound like correct behaviour of danio males and females? If so I should have 4 males and 5 females 🙂
Robert Brand says
First of all, how do you know they haven’t spawned when placed in the breeding tank? Were they separated before hand? If not, then they would have likely bred in the tank already, and adding them to a breeding tank wouldn’t do anything. Also, they’re pretty indiscriminate breeders, so it’s no usually necessary to find a mate to pair off with.
As for the scratches, they are often from attacks, or fish catching themselves on decorations in the aquarium. Do you have any sharp surfaces in there? And if they’re from attacks, they’re not really scratches, but scales that have been pulled off.
Now on to the flaring: it is either males being aggressive towards each other, or mating behavior. So you may have both males and females doing it, and it can be sometimes difficult to know why.
If you’re serious about breeding, the best thing to do is to separate the males and females a minimum of two weeks, and condition them with live and frozen foods. Then, right before the lights go on, introduce them a breeding tank, with a substrate like marbles, so they can’t reach the fallen eggs. After a few hours, remove them, and keep trying pairs until you can spot eggs in the aquarium. If you do this, I promise you’ll be able to breed them. There is more information in the article as well, so look it over for further tips.
I hope this helps.
sai says
are there any fish for guppy population control,
Robert Brand says
Most fish will actually eat guppy fry, but if you guy some for the adults, you’ll probably lose all of them.
If you are dead set on getting one, Angelfish are quite good at controlling them – assuming the tank is large enough.
Megan says
I started a new job and already had fish in my office so I have no idea what any of them are. There is one fish I have been keeping my eye on for the past week and after reading this I believe it is a Zebra Danio. I first noticed him as he had a curved spine and seemed to always stay in the top quarter of the tank. I have come in this morning after a long weekend to find him isolated in the same corner of the tank all day, swimming around wonky and in circles, and even bobbing up for air every few minutes. All other fish seem fine and all eating, however the other fish are much quicker than my poor little Danio so I don’t feel he is getting a proper ‘meal’ so to speak, he is just lucky to already be at the top. Advice asap would be appreciated and I am happy to send you some images of the fish, i just can no longer ignore him guilt free, and I dont want the other fish to be affected by whatever might be wrong with him.
Robert Brand says
It might just be old age, as their spines get bent as they age. Or it might be fish TB, which is pretty nasty. Are there any lesions on the body? Lose of scales? Bulging eyes? If it’s fish TB you need to be careful, and remove the fish ASAP.
Let me know.
Megan says
His tail fin looks as though it has been ripped but that has only happened in last few days as it wasn’t always like that. Its flaking away almost. Its eyes aren’t bulging however the lump that is on its side is starting to turn a pink colour but it looks like the pink is coming from under the scales almost looks like when a human has a coldsore ‘coming on’ – like a pink pimple under the skin. the way in which the fish bends is around towards the lump and thats the only direction it swims in.
Emma says
Hi tHere so I Have 5 day danio fisH and one seems to be very plump and wHen He swims He looks lopsided.. What is the cause of this? Could it be pregnant?
Robert Brand says
It’s not pregnancy, but it could be bloat or a swim bladder disorder. Try feeding it lightly boiled and shelled peas to see if it clears up first. If not, then you want to treat with antibiotics – preferably in another tank.
Tania says
I have been trying to breed Danio dangila which is another species of Danio for last 2years. But still can’t able to breed Danio dangila in aquarium.Its urgent as this is required for my Ph.D.
If possible help me.
Robert Brand says
Unfortunately, these are a notoriously difficult fish to spawn. From the reports I’ve read, you have one of two options: either place them in a densely planted aquarium and hope for the best, or place them in a traditional setup, and once again, hope for the best.
While there are numerous documented incidents of them spawning in heavily planted tanks, it’s really leaving everything up to chance. Java moss and floating plants will help the odds of some surviving, but best case scenario is that you only get a handful of fry.
And doing the traditional method is no better. The males are relentless in their pursuit of the females and it rarely yields positive results in the tried and true aquarium with marbles on the bottom. However, I have heard conditioning the males and females separately on livefood first and then placing several males and females in a breeding tank can work. But apparently changes in barometric pressure play a role in triggering the spawning.
I wish I could help more. If you have any more specific questions, please let me know.
Tania says
Thanks for your response. I have set up breeding Aquarium. I put gravels at the bottom, placed breeding mop but nothing fruitful has come.The main difficulty is sex differentiation.Faced problem regarding the gonadal maturation. I have given photoperiod treatment to induce gonadal maturation but not much success have found in case of female. If you have any more information about this please let me know. Thanks once again 🙂
Ginger says
I have zebra danios that recently laid eggs, but I don’t think they are fertilized. How soon will she be able to lay again?
Robert Brand says
If there are males in the tank, they are most likely fertilized. What makes you think they aren’t?
And it usually takes a few weeks of conditioning with good food for the female to plump up with eggs again.
Pranab Jyoti Goswami says
Dear Sir/Madam,
I need help regarding Pink Danio grow up. In my tank I have successfully spawn Zebra Danio and Pink Danio. In the first phase I observed more than thousand free swimming frys. But finally I got only about 50nos of fry alive. I observed that their growth is very slow. In 4-months they are about 1cm to 1.5 cm in length. And observed some of fry’s belly swollen by eggs. Is it the normal or I need to do something for their better health as well as better growth.
I feed them with Infusoria, egg yolk and after that Hikari First byte. Some time I used finely crashed adult fish foods viz. “Royal Pet Tetra Bits Complete”, “Taiyo Aini Fast Growth Fish Food”, “Hikari Tropical Micro Pellets” & “Hikari Tropical Micro Wafers”. And my Grownup tank is “Length 2ft x Breath 1ft x Height 1ft” about 40 to 45 Litre of water.
Please guide me with right way.
Thanking you,
With regards,
Pranab
Robert Brand says
It sounds like you’re doing all the right things from what I read in your comment. If anything is wrong, I’d probably say you’re having issues with water quality. Is the tank fully cycled before you breed them in there? Are you keeping the tank clean as they grown? Have you tested the water at all?
ZsaZsa says
Your patience is commendable. I cannot believe people have been asking you the same stupid questions for years, or that you have politely and thoroughly answered them all.
Robert Brand says
I honestly don’t mind helping people and hopefully I can help a few fish live better lives by giving people the proper information.
Kaden L says
Hey Robert.
I recently got a 10 gallon tank with 3 plants on one side, some buildings on the other, with some gravel. I have a nice filter in there, and it has a heater that I can use when the time comes. For my fish I chose to get a total of 5 Long Finned and regular Zebra Danios. I was wondering if I’m going to be able to fit more fish in, or if it’d become too cramped for them to live in. I think I’m doing everything right, and want to know if I can add another in. Any help will be nice. Thanks!
Kaden L says
I was also wondering if a betta fish would do nicely in the tank as I’m told that they do ok in a community environment. I don’t fully believe those sources and would like your confirmation.
Robert Brand says
There are few fish more difficult to accommodate in an aquarium than bettas. If they are placed with fin-nippers, their long flowing fins will be shredded. If they are placed with docile fish or fish with flowing fins like guppies, they will relentlessly harass them. But if placed with larger, aggressive fish, the bettas will be bullied and may be eventually killed. My personal recommendation is to avoid male bettas in community tanks, as I’ve never been able to make them work. However, I have had some luck with female bettas, and they can be kept in groups of up to six. I can describe how a female harem of bettas will work if you’d be interested in that.
Kaden L says
A Harem of bettas sounds pretty interesting. What’s that?
Kaden L says
Also, I am interested in breeding my fish. any info on that?
Robert Brand says
A good rule of thumb when keeping fish is to have around 1 inch of fish for every gallon of water. This is a very rough rule, as it doesn’t account for wide-bodied fish like goldfish, or the fact a ten-gallon aquarium won’t really have 10 gallons of water, due to the substrate taking up space, etc. But going by this calculation, you’re pretty well at the limit of what you can safely keep in there. However, if you want to add more activity or colour to your aquarium, then you can still add snails (avoiding large snails like apple snails) or shrimp. Both of these have small bioloads and look excellent in aquariums.
Kaden L says
My fish have been very aggressive towards each other, and it hasnt been establishing their pecking order. They all go to one tank and it gets very violent. My male died a few days ago so it’s all females. Would it be best to go back and get another male?
Russ Checketts says
My female just layed eggs in a community tank. Is there anything I can do to save the eggs?
They were fertilized, and I have neon tetras also in that tank.
Corinne says
I have 4 zebra danios and 3 neon danios in a 15 gallon tank that also has a bristle nose pleco thoughts?
Robert Brand says
It’s going to be a little tight with those fish but there shouldn’t be any real problems. Just keep on top of water changes and don’t overfeed and you should be fine.
Summer says
Hi My golden danio belly is plumb and I am not sure if it is female or male and I am not sure if it is pregnant or not or what to do if it not pregnant
Please respond
Robert Brand says
Generally speaking, if it’s just slightly plump, then it’s likely carrying eggs. But if it’s really distended, then the fish may have bloat. Is it showing any other symptoms of distress?
Deborah says
I had the hardest time getting babies to survive.
They didn’t seem to survive on the Firstbites alone and the baby brine shrimp were actually too big for them to eat during the first few weeks. I looked at them under the scope and could see that it was impossible for them to eat the baby brine shrimp. I had batch after batch die at about 15-17 days post fertilization, which would indicate starvation.
It wasn’t until I ordered a moss that just happened to have paramecium in it, and inoculated the tank, that I had some survive. I now firmly believe that they need the paramecium during the first few weeks.
Robert Brand says
I mainly use infusoria myself, and while many people swear by baby brine shimrp, I’ve always had better luck with infusoria. It’s interesting that you’ve had such poor survival rates with baby brine shrimp, and I think I’ll need to do some experimentation with this.
Chris says
Hey man, late to the comments, I got a 29 gal tank, 12 tetras bleedin hearts, two river loaches, and a old black pleco, like 15 years old, can I get 5 or 6 of these top zebra Danios, or am I overstocked already, I gravel vac once every two weeks, sometimes every week. Let me know fam
Robert Brand says
Honestly. you’re already at your limit, especially with the pleco, since those are large and very dirty fish. If you add a school of danios, you’ll probably run into problems.
Krishr says
Hi,
I have a 15 gallon tank with 1 pair of zebra danio and 2 pairs of giant danio. I introduced 3 pairs guppy and 3 pairs Molly.. But all died in 2 days. My tank is 5 weeks old and I introduced the new fishes only after 5 weeks. This is the second time it’s happening…I am not able to add any new fishes to the zebras. What am I doing wrong? Please help.
Robert Brand says
It’s difficult to say what’s happening to your fish. Were there any sick fish in that tanks at the pet store? How often are you changing water in the tank? Did you acclimatize the fish to the water before adding them?
Bex says
Hi I have a 3 gallon tank that I had 2 glofish tetras I’m but they got ich and unfortunately died. I throughout cleaned the tank and let it sit and reestablished it. I just added 2 glofish danios in it that are about 3/4 of an in each. One of them always seems to be chasing the other and I can’t tell if it’s aggressive or they are just playing because then the one that is being chased tried to jump up out of the tank by the filter. Is this normal? Are they going to be depressed being only the two of them. I’m a college student and I can’t really get a bigger tank
Robert Brand says
Do you have any ornaments of plants in the tank? It sounds like they’re displaying aggression and having something to break the line-of-sight should help things in your aquarium. But if you can upgrade in the future to a larger tank, you should try to do so as the fish prefer larger groups.
Sam says
I have a 5 gallon fluvial chi aquarium with one surviving zebra fish I had rescued, It has been in there alone for about 6 months now and it seems to be happy. Swims around like a mad man lol. I feed it freeze dried blood worms as a treat every time I change its water. I do I would say about 10-20% water change once a week. Currenently I have sand a fake plant and a little cave in the tank. Should I get another fish or is it fine that I only have the one. I’m afraid that because It has been alone for so long It would become aggressive and it does seem happy. Im also thinking about getting some real plants any recommendations?
Robert Brand says
Zebra fish are pretty large, so it’s hard to recommend any more. But they are also schooling fish and do best with more of their kind. I think if you’ve very careful, you could add another two fish to the aquarium, but someday you should try to upgrade to a 10 gallon tank or larger. It’s best to keep at least five of these fish together.
As for plants, these ones are pretty easy to keep: Java moss, Java fern, Cryptocoryne wendtii, Amazon sword (will eventually grow too large for a 5 gallon), and Marimo moss balls.
Mimi says
Hi. I have been reading your information and comments regarding Danios. I have 6. In a 22 gallon tank with a clown pleco and 6 tetra. Everyone doing well except 1 danio which has gone super thin. I noticed this 3 weeks ago and danio is still alive but hides behind filter output until feeding time. Have fed her (I’m pretty sure female) extra feeds by taking her out of the tank. I realise that’s stressful for fish but I don’t know what to do. I don’t have a hospital tank. My water parameters are all fine. Other fish doing well. I did have one tetra that went thin but has since recovered. I have used an anti bacterial in the tank in case infection but it looks like bullying. I can’t see any damage. I’m going to take the fish to local store as we are going on holiday on Saturday and I’m worried it won’t survive. Any tips or thoughts you may have on the situation would be great. Thank you.