The Zebra Danio (Zebrafish) is a sprightly little striped fish that is a natural addition to any new hobbyist’s list of species to have.
Often known as Zebrafish, they may also go by the name Striped Danio, but however you are introduced to this little species, it’s clear where they get their common name from.
Found in the flowing freshwater streams or pools of India, Nepal, Bangladesh, and surrounding areas, they are a very hardy bunch indeed. Some eye-popping statistics abound for the conditions these little guys can thrive and even flourish in. We’ll discuss more on those a little later.
Zebra Danios have a varied history and even some historical significance. A little freshwater fish like this? How, you ask?
Some fun facts about the humble Zebra Danio:
- They have been sent into space by NASA
- They have their very own dedicated scientific journal and have been fully genetically sequenced
- They are a research organism used for the study of vertebrates
- There are some who can fluoresce through modification using jellyfish genes
- They have been used in stem cell, regeneration, drug, and even cancer research
Whew, that’s a lot for one small freshwater fish! Chances are that some of the research that Zebra Danios have been involved in may have saved or impacted the life of you or someone you know.
And yet, they are ubiquitous in aquariums the world over as an admired and attractive fish to have in your tank.
Why are they such a popular addition to tank communities? We’ll delve a little deeper as we go through this article.
Zebra Danio Behavior
Zebra Danios are pretty easygoing fish on the whole. They are a shoaling species, so you should always have a group and avoid keeping one on its own, which would be ill-advised.
Groups will often display various levels of dominant behaviors. There is a definite pecking order which can be fun and interesting to observe to their keeper and the casual observer.
What might look like in-fighting amongst the group is actually more often attributed to playful behaviors akin to a little light teasing among friends. The Danios are active swimmers and can be seen chasing each other around and playfully antagonizing one another.
If a very large shoal of Danios is kept in your tank, you may expect to see some serious activity and taking up all space in the tank at every level. They will act like busy bees in a hive and zip all over the place.
On the other hand, a singular Danio is a lonely Danio and will often hide instead of engaging or looking interested in their surrounding. This can lead to them being quite stressed and prone to illnesses since they aren’t behaving as they normally would, which is super active.
Another point to note is that you should take precautions with slower-moving fish who have long, flowing fins. Danios are known to nip and pluck at those tempting fins, and encounters can border on the aggressive or bullying.
Zebra Danio Lifespan
Healthy and well-kept Zebra Danios live on average anywhere from 3.5-5 years but can live comfortably up to a ripe old age of even 6 years, which is quite a long time for such a little fish.
We will discuss more on tank requirements a little later in this article.
Zebra Danio Appearance
Zebra Danios have an appearance rather evocative of their name. This is to say that they are horizontally striped and typically have five pronounced, dark blue stripes that are iridescent and run the full length of their bodies.
Body shape is long and rounded, like a little missile. Body base colors are usually pale gold or sometimes silvery-gold in tone, and they do have some striping present on their caudal and anal fins.
Their mouths are upturned, giving them an almost pouty look.
Males tend to be more golden between striping, whereas females look more pale and silvery between striping, so they are fairly easy to distinguish.
Topping out at about 2 inches in length, they are wee fish but make an impact in their shoals.
Naturally, you might expect that with all the prior talk about research and genetic tampering with these fish, there are some variations in the aquarium community. These differ wildly from naturally caught Zebra Danios, who are substantially less flashy.
Many would argue that only wild-caught Danios are worth having in your aquarium, but there is a fashion for everything, and some fish keepers are relentless about having more avant-garde types.
Some of these varieties include:
- Manmade transparent Zebra Danios (zero pigmentation and all organs visible, not available to purchase)
- Long Fin Zebra Danios (try keeping those in a shoal and expecting those fins to stay in shape given their behavior!)
- Golden Zebra Danios who have a very yellowy background
- Albino Zebra Danios who look whitish-pink
- Genetically modified GloFish who glow under fluorescent lighting and can be found in green, pink, orange, purple, red, and blue shades
Zebra Danio Habitat And Tank Requirements
For the healthiest fish, all aquarists should aspire to recreate their natural habitats as closely as possible.
Since Zebra Danios are freshwater fish from slow or sluggish moving waters, it is important to keep water movement to a minimum.
In the wild, they love a lot of lush vegetation and silty river or rice paddy bottoms to swim around in, so we will take a look at what suits them best for a tank setup.
Tank Conditions
Since Danios enjoy slower flowing water, you’ll want to keep filtration sufficient but not overly aggressive. Hang-on-back (HOB) filters are ideal for these fish, but sponge filters will help as they are small, and consistent fry production is another consideration.
They love silty substrate, which means smaller than sand but less diminutive than clay particulate. Natural rocks should be a part of the terrain, and ideally, you want some floaty plant life as might be found in rice paddies or slower moving waters.
Ideal plantlife for your tank should include Duckweed, Amazon Frogbit, Hornwort, Java Moss, Red Root Floater, and Amazon Sword Plants. All of these plants will assist with the tank oxygenation. Include elements such as dogwood, rounded pebbles, and anything that will mimic tree roots.
These little fish enjoy light, and being tropical; they will enjoy and happily tolerate 12 hours of light.
Hiding spaces should abound, whether it be through plants or artificial caverns and rocky areas they can duck into. Lighting should be medium in intensity, nothing too bright or dim.
You will want to avoid jagged-edged decor on any level because they are such prolifically fast swimmers and can be inadvertently pushed into tank items.
Another important point to note is that these fish, while small and diminutive in stature, are great little jumpers! If at all possible, have a lid on your tank to avoid unnecessary fatalities from your community!
It’s important to note that these fish are incredibly hardy. They tend to handle whatever conditions you throw at them. This not only includes temperature swings but also fluctuations in pH.
There are many people who say that they are great for creating tank cycles, but sympathetic fish keepers would argue that this is still not an ideal condition for these fish. Just because they can survive doesn’t mean that it’s a good idea to ask them to in order to cycle your fish tank.
Water conditions (this is a reference to ideal conditions) should be noted and maintained as follows:
- pH of 6.5-7.0
- Water hardness between 5-12 dGH
- Temperature between 64-77 ºF (18-25ºC)
- Lighting can be kept median
Tank Size
The minimum tank size needed 10 gallons per Zebra Danio.
You can have one Zebra Danio per 2 gallons of water beyond that, so that shoaling is possible and ideal for their health.
They need a lot of active swimming space to thrive and prevent stress. Keeping them interested and engaged is important for their health.
Choosing Tank Mates For Zebra Danios
It’s very important to consider what is best for the fish species you choose to care for as an aquarist when considering tank mates.
Educating yourself and doing the research necessary to have a harmonious environment is a key aspect of being a quality fishkeeping enthusiast.
Some excellent fish tank mate pairings for Zebra Danios are:
- Indian Flying Barb
- Honey Gourami
- Scarlet Badis
- Emerald Pufferfish
- Ember Tetra
- Rosy Barbs
- Dojo Loach
- Zebra Snails
- Africa Dwarf Frogs
- Blue Velvet Shrimp and other freshwater shrimp
- Nerite Snails
- Places
- Corydoras
- Rainbows
Zebra Danio Common Health Issues
If you have Zebra Danios, you are unlikely to encounter any major illnesses. There are the usual culprits for freshwater fish such as Ich and other bacterial infections common to all species in this type of environment.
It’s important to realize that although these fish are hardy, they should not be an afterthought when it comes to tank conditions and their maintenance. You should still be regular in your water changes and monitoring of nitrates, ammonia, and pH.
One additional issue that can be prevalent for Danios is Mycobacteriosis. This is often identified by symptoms such as anorexia, inflammation, ulcerations on the body or fins, swelling of the body, and general lethargy.
In general, if any Danios get an illness, there isn’t a huge amount of treatment available to them, but isolation is best to prevent any further infection of other fish in your tank community.
How To Breed Zebra Danios
If you are a novice aquarist, chances are you will have Zebra Danios at some point in your entry to the hobby.
They are very simple and easy to breed and make a satisfying species to have if you wish to attempt breeding fish in captivity.
Male and females do exhibit sexual dimorphism and can be distinguished from one another with a keen eye and attention to detail.
Despite their reputation for being prolific reproducers in the tank community, they do have a surprising trait which is that they tend to mate for life! Once they pair off, and a partner’s death notwithstanding, they will spawn for life.
Not that they need any encouragement, but if you need to help things along, you can isolate a breeding pair into a shallower tank with about 6 inches of water. If you increase the temperature to about 78 degrees plus (25C), this will encourage spawning.
You will need some coarse substrate so that the tiny eggs have somewhere to drop into that will protect them from the adults who will consume their own eggs.
Once eggs are visible, remove the breeding pair, so they aren’t present to eat the eggs or the subsequently hatching fry. Danio fry will hatch quickly, normally within 48 hours of fertilization, so you do need to be observant to protect them.
Due to their incredibly tiny size, a sponge filter is a must, but extra care should be taken when it comes to water changes also as they are barely visible and will often be swept into the change.
Conclusion
In summation, Zebra Danios are one of the most ubiquitous but possibly underrated little fish in tank communities today.
They have played an unusually integral part in the health and understanding of biological systems and processes of humans, which is quite fascinating. When you consider them as tiny little vertebrate fish, their impact is quite astounding.
All in all, they are a fascinating species to keep, and not only will they be entertaining to observe and admire, but they will be educational from a breeding perspective.
You can tell your friends that your little friend in the tank has been to space, and not many of us on planet Earth can say the same. Pretty cool for a little fish.
