Zebra Fish / Zebra Danio
Zebra Fish is Native to Ganges region in India & Bangladesh, they live in slow moving shallow waters & paddy fields. Zebra Danio is a Tropical Freshwater fish also called Striped Danio or Zebra Fish as they have horizontal blue lines on their body which resembles the stripes on the Zebra, these 5 to 7 lines run from the gills to the tail. The scientific name is Danio rerio, this fish can grow up to 2.5 inches in length & the average lifespan is 1 year in the wild & up to 5 years in an aquarium with proper care.
Zebra Fish are hardy fish they can withstand drastic change in water condition in their natural habitat, they tolerate temperature ranging from 6 degree Celsius (42.8 Fahrenheit) in winter to 38 degree Celsius (100.4 Fahrenheit) in summer. They are omnivores, they commonly eat zooplankton, aquatic insects & mosquito larvae.
Few things you should know about Zebra Danio, it was the first fluorescent fish or GloFish which was genetically engineered by extracting green Fluorescent protein from jelly fish & inserting it into embryo of Zebra fish. Fluorescent fish maybe illegal to own in few countries, so check before you get them.
Also Zebra fish are used in lot of experiments by scientist, they were taken into space to study muscle changes in them at micro gravity. Apart from this Zebra fish is used in scientific research in medicine, as they can regenerate damaged heart in larval state & other complex tissues.
Visual differences between Male & Female Zebra Fish
Visual differences can be seen once Zebra Fish is fully grown, male Zebra fish appear a bit smaller in size compared to females; males have flatter under belly where as the female Zebra fish has a rounder belly area, this is because the female zebra fish holds eggs & the belly gets larger when she is ready to breed.
Zebra Fish Aquarium Care
Zebra fish is a great option for beginners in the hobby, they are hardy, they are fast & they make great compatible tank mates for various similar sized & temperament freshwater fish. If you have a non- aggressive shy fish in your aquarium adding a school of Zebra Danio's would help the shy fish to be more confident & come out, as these fish are super active or rather hyper active. I use Zebra Fish in my Betta tanks as tank mates, if the Betta is aggressive it will try to chase the zebra fish which are super fast, eventually the Betta gives up & learns to live with tank mates in few days. These fish have wider pH range, temperature range than any fish I know off in the fish keeping hobby. This makes Zebra Danio a prime option for someone who wants to get into the fish keeping hobby. Below information will help understand their requirements in an aquarium.
What your Zebra Fish needs
Things to buy & Why?
Aquarium : Rectangular shaped Aquarium is advised for Zebra Fish, since Zebra Fish school & are fast swimmers, lot of open area in the Tank has to be dedicated for them to swim. Zebra Fish spend most of the time in the middle & surface area. They should be kept in a Community Tank with other Zebra Fish (at least 6) or other similar size Fish like Mollies, Guppies, Platies, Sword Tails etc.
Heater : Temperature range is 65.0 to 77.0° F (17.8 to 25°C). Depending on the location & size of the Aquarium an Ideally sized heater is required. (Bigger Aquariums might need more than one or bigger heaters)
Substrate, Plants & Rocks : Zebra fish like to swim around & they are fast swimmers. When decorating the tank keep in mind Zebra Fish hang around in the middle & surface area. Zebra Danio's aquarium can be decorated with live plants, rooted & plants which grow to surface. During spawning they prefer Java moss as the females scatters the eggs in it. Driftwood & rocks can be used to decorate the tank, I have used pebbles, plant substrate, sand & just bare bottom with Java moss & they seem at home in any kind of tank decoration.
Thermometer : This will help monitor the temperature, if you are located in a colder climate or non-tropical or sub tropical location with changing weather, you need a heater & a thermometer to monitor temperature. Remember there should never be drastic changes in water temperature, sudden change in water temperature beyond 2 degrees a day may cause serious damage to fish, always maintain a steady temperature.
pH test kit : pH range for Zebra Fish is 6.5 to 8, pH test kit helps you monitor fluctuations in pH levels in aquarium, this is really handy when a new aquarium is set-up as water parameters drift drastically causing serious damage in fish. In case there is increase in ammonia, nitrite or nitrate, this will let you know when water change in needed in your aquarium & how much water to be changed.
Lights : If you are planning on live plants in your tank, make sure you get suitable light for your plants. If you get artificial plants any small Light will do. Just make sure the light you install is bright enough & does not heat up the water in the tank too much. Plants which require low light can be considered like Java Moss, Java Fern, Anubias, Vallisneria, Sagittaria, these plants do well under small LED lights.
Filter/Air pump : Filter will help you keep the tank clean & an Air pump will keep the tank nicely oxygenated. Remember the water movement caused by the filter & air pump should be minimal. Zebra fish prefer moderate water movement. They do just fine even with a sponge filter powered by an air pump.
Water conditioner : Tap water in most cities are treated with chlorine. This is bad for your fish. So get a water conditioner, this will make the water 'fish safe'
Fish food : Zebra fish are Omnivores they will eat pretty much any fish food like pellets, flakes, freeze dried worms, if you have access to live food from your nearest Local Fish Store, you can feed them live food like daphnia, micro worms, blood worms, mosquito larvae etc. Its advisable to feed them twice a day & feed only as much as they can consume in 2 or 3 minutes.
Fish net & Aquarium vacuum/Gravel cleaner : Once you have an aquarium set up, now you would need to do your aquarium maintenance. Usually 10% to 50% water change is followed depending on water conditions. A Fish net will help when cleaning the tank & if needed to move fish to another location. Gravel cleaner is easier & effective way of cleaning the tank bottom, just vacuum the tank bottom of debris & add freshwater.
Additional Supplies : Adding a little Aquarium salt in the tank during water changes is a good habit to keep the fish healthy, an alternate in aquarium below 7 pH is Indian Almond Leaf, half a leaf for small tanks would also keep the fish healthy. You can consider these things when setting up a tank.
Tank Mates for Zebra Fish
Zebra fish is a great option for beginners in the hobby, they are hardy, they are fast & they make great compatible tank mates for various similar sized & temperament freshwater fish. If you have a non- aggressive shy fish in your aquarium adding a school of Zebra Danio's would help the shy fish to be more confident & come out, as these fish are super active. I use Zebra Fish in my Betta tanks as tank mates, if the Betta is aggressive it will try to chase the zebra fish which are super fast, eventually the Betta gives up & learns to live with tank mates in few days. These fish have wider pH range, temperature range than any fish I know off in the fish keeping hobby. This makes Zebra Danio a prime option in a community aquarium, they would just school on their own and even escape from any fish which tries to get to them.
In case you want to set up a community tank with Zebra fish in it, make sure the aquarium is at least 20 gallon or bigger. Zebra fish should be kept in a school of 6 or more, the reason is when a schooling fish is kept alone or with just 2 or 3 of its kind, they seem to change their behavior, I've observed a single Zebra being less active & even chasing Guppies. Hence, 6 in a school is a decent size for them to establish a hierarchy & keep them busy with their own kind. If you observe closely in most schooling fish the dominant fish always leads.
I've included Zebra Danio with a variety of tank mates like Betta Fish, Molly Fish, Guppy Fish, Swordtail Fish, Platy fish, Dwarf Gourami, Rasbora, Threadfin Rainbow fish, Neon Tetra, Blue Ram Cichlid, Black Diamond Tetra, Glowlight Tetra, Cherry Barbs, Corydoras, Serpae Tetra, Angelfish, Shrimps, Apple snails & the list goes on. Any same sized non- aggressive fish can be kept with them, even though fish like Betta or Angelfish who are aggressive can be kept with Danio rerio as these fish are too slow to bother them.
Breeding Zebra Fish
Zebra Fish are egg layers, they spawn & scatter their eggs, they mature in about 3 to 4 months of age. Danios prefer Java Moss or densely planted area in the aquarium to spawn. Once a female reaches maturity her belly area is filled with eggs, irrespective of a males presence the female would lay the eggs; the eggs are eaten in most cases. In case of a Male Zebra Fish is present in the tank, he would fertilize the eggs as soon as the female releases the eggs. The uneaten & fertilized eggs are hatched into fry in 3 days. Zebra Danio's can spawn every 10 to 20 days.
In case you want to breed Zebra Danio's & want to have a high fry survival rate, this can be done by first triggering the spawning, generally a water change followed by increase in temperature by 2 degrees triggers spawning, temperature range for spawning is between 78° F & 80° F. Most breeders use a net or tray with small gaps & breed this fish in a separate breeding tank. The eggs fall into the gap where the adult Zebra Fish cannot reach to eat them. The eggs are then collected & in 3 days are hatched into fry.
Other option to breed Zebra fish would be using Java Moss instead of a tray. First a breeding bare bottom aquarium is setup with a sponge filter in a corner, add java moss to the bottom of the aquarium, use small stone or pebble to sink it to the bottom by laying the stone on it. Move the adult Zebra danios to this tank, once they are settled in well, do a water change & increase the temperature by 2 degrees a day until you hit 78° F to 80° F. They love this set up as you would see them spawn instantly. Once they have spawned remove the adult fish. In 3 to 4 days you would have free swimming fry. Depending on the Female Zebra Fish size & age she may lay up to Zebra fish fry can be fed crushed flakes, baby brine shrimp, infusoria etc.