Zebra Danio (Danio Rerio): Ultimate Care Guide

Zebra Danios (Danio Rerio) have slender, silver bodies that have blueish-purple stripes that run horizontally along their length from gil to tail. These stripes are what give them their common name of Zebra Danio, and they also make it so these little fish are easily identifiable. They are a popular choice for home aquarists due to their flashy appearance, and active nature.

Zebra Danio Facts

  • Even though Zebra Danios can reach up to 3 inches in length at full maturity, they rarely get to that length, especially in captivity.  This micro size and smaller tank requirement makes them a popular choice for home aquarists who have a limited amount of space.
  • Zebra Danio are one of the most heavily researched fish that have become a model for scientists to explore the DNA of the fish. Scientists have even sent Zebra Danio into space.
  • The DNA of the Zebra Danio was fully sequenced in 2001, and it is still studied to this day in laboratories around the world.
  • Zebra Danio share roughly 70% of their genetic material with humans so they are ideal for studying human diseases and developing treatment. 
Common NameZebra Danio
Scientific NameDanio Rerio
Temperature79F – 88F
Water pH6.5 – 7.0
Adult Size2.5 to 3 inches long
Zebra Danio (Danio Rerio)
Zebra Danio (Danio Rerio)

Zebra Danio Care

Zebra Danios are easy fish to care for, but they do require some knowledge to set up their habitat, and ensure that they are fed the proper diet. It is important for the happiness and comfort of the fish that they are housed in the appropriate sized aquarium that mimics their natural environment. Zebra Danios are schooling fish that do best when kept together in a group as well.

Food and Diet

Zebra Danios are omnivorous, opportunistic feeders that eat a variety of foods. In their natural environment, Zebra Danios eat small crustaceans, worms, insect larvae, plants, and algae. In captivity, Zebra Danios will eat a mainly plant based diet and should be offered algae wafers, high quality fish flakes, and even chopped up green veggies like spinach. To meet their dietary requirements, Zebra Danios should also be offered frozen or live foods such as Daphnia or Brine Shrimp once or twice a week.

It is very possible to overfeed Zebra Danios, so the feed amount should be monitored. Overfeeding can lead to bloat and obesity. It is important to establish a regular feeding schedule so that you can avoid any potential dietary issues. It is recommended that Zebra Danio are fed small amounts of food 2 to 3 times per day. This helps regulate their digestive system, and will help prevent blockages from waste buildup in their bodies.

Size & LIfespan

Zebra Danios are a little on the small side even when fully grown. At full maturity you can expect Zebra Danios to reach 2.5 to 3 inches long. In captivity, Zebra Danios do not often reach the full 3 inches. If they are cared for properly, they can live anywhere from 3 to 5 years in captivity.

Tank Requirements

Due to their compact size, Zebra Danios require a tank of at least 10 gallons to house the recommended minimum sized school. They require 6.5 to 7.0 pH and a warmer temperature that is maintained at a range of around 79F to 88F. This means that you will need to invest in a reliable heater for their tank as well as do regular water parameter monitoring so that you can correct any issues as they arise.

How Many Zebra Danio Can You Keep in a 10 Gallon Tank?

If you have limited space in your home for a Zebra Danio aquarium, then you are in luck. You can keep up to 5 Zebra Danios in a 10 gallon tank. A good rule to follow when deciding how many Zebra Danios will fit into your tank is to keep 1 gallon for every 1 inch of fish. Zebra Danios can reach up to 3 inches at full maturity, but that rarely happens in captivity.

Tank Setup

When setting up a tank for Zebra Danios it is best to set it up as close as possible to their natural home environment. The best substrate to use for Zebra Danios is a soft, sand or mud substrate. You can add a few small rocks for a more natural look, but try to avoid large or sharp rocks as they could potentially injure the Zebra Danio as they dive down towards the bottom of the aquarium. Choosing a darker substrate is best to help their flashy colors to stand out against the background instead of blending into it.

If you are wishing to further show off their coloration, a blue light is recommended. Other than the blue light, Zebra Danio requires regular aquarium lighting that is also suited for plant growth. For decor, Zebra Danios will be happy with bogwood and river stones. Floating and planted, Zebra Danios are happy with lots of vegetation in their tank, in fact, there is a high chance that they will be caught snacking on your plants as they prefer plant matter in their diet. Owners of Zebra Danio have mentioned success in keeping them in a planted tank when they are juveniles but as they matured they began to devour the plants.

It is important to make sure that your Zebra Danio tank has a secure lid to prevent them from jumping out as well as helping keep water from evaporating.

Breeding Zebra Danio

It is possible to tell Zebra Danio males from females by simply looking at them once they reach full maturity, but the differences are slight. Adult male Zebra Danios are more slender and tend to be smaller than the females. Female Zebra Danios have more rounded and larger bellies.

Zebra Danios are considered prolific breeders, and are one of the easiest fish to breed in captivity. They tend to pair off when they are ready to spawn, and the mating pair will remain a pair for the rest of their lives. They will not spawn with another partner even if their partner dies. The easiest way to get a breeding pair is to start with a small group of juveniles, and allow them to mature together. This way ensures that you end up with at least one male and female.

How Do Zebra Danio Breed?

If you are looking to breed Zebra Danio, then you will be happy to know that they are one of the easiest fish to successfully breed in captivity. It is a good idea to set up a dedicated breeding tank for your Zebra Danios.

When Zebra Danios are ready to spawn, the female will lay her eggs scattered around. The female will lay around 100 eggs at a time, and the male will then fertilize them. Once the parent fish are done spawning, they should both be removed from the breeding tank as they will eat their own fry.

How Often Do Zebra Danio Breed?

Zebra Danios can spawn every few weeks, but this is not a problem as the mature fish will eat the fry once they hatch. If you wish to ensure the survival of the fry, you will want to set them up in a dedicated breeding tank.

How Can You Tell if Zebra Danio is Pregnant?

Even though you can visibly see your Zebra Danio female growing rounder as she nears spawning time, this does not mean that she is pregnant. She is simply full of roe or eggs. The eggs she carries inside her are empty; they will not contain fry until they are laid and then fertilized by the male.

What Do You Do if Your Zebra Danio is Pregnant?

If you suspect that your Zebra Danio female is full of eggs, and you are wanting to keep the fry, then it is advisable to move her and the male to a breeding tank for the safety of the eggs and newly hatched fry.

How Are Zebra Danio Eggs Laid?

When Zebra Danio females are ready to spawn, you will be able to noticeably see them grow more rounded with eggs. This is your cue to move the breeding pair into the breeding tank.

When the female begins to lay her eggs, the male will begin to chase her around until she drops all of her eggs.

Zebra Danio females lay their eggs around the bottom of the aquarium. The female Zebra Danio can lay around 100 eggs during spawning. The eggs do not stick to surfaces, and will slip down into cracks and crevices in gravel or substrate.

Where Do Zebra Danio Lay Their Eggs?

Zebra Danio females lay their eggs on the substrate. The eggs are not sticky and do not adhere to any surface. Usually the Zebra Danio eggs slip down into the cracks and crevices where they will lay until they are ready to hatch.

What Do You Do With Zebra Danio Eggs?

If you suspect Zebra Danios have laid eggs in your aquarium, then you have two options. The first option is to leave them be, and let the parent fish eat them. The second option is to separate the fish from the eggs. Zebra Danios provide no parental care to their offspring and will eat their own fry. Zebra Danio eggs hatch in about two days, and the fry will become free swimming.

Do Zebra Danio Eat Their Own Eggs?

Zebra Danios provide no care to their offspring, and will cannibalize their own fry if given the chance. If you are wanting to keep your Zebra Danio fry to raise, you will want to set up a dedicated breeding tank.

How Can You Tell if Zebra Danio Eggs are Fertilized?

You can not tell if Zebra Danio eggs are fertilized by simply looking at them, but the good news is that they do not take long to hatch. The eggs usually hatch and the fry become free swimming in about 2 days.

How Long Does it Take for Zebra Danio Eggs to Hatch?

Once the Zebra Danio eggs are laid they take around 2 days to hatch.

Zebra Danio Fry

The first thing you need to do to ensure the life of your Zebra Danio fry before they ever hatch is to remove the parent fish from the tank, or relocate the eggs. Zebra Danio fish provide no parental care to their offspring, and will even eat them if given the chance.

What Do You Feed Zebra Danio Fry?

You would care for Zebra Danio fry a little differently until they are large enough to eat flake foods on their own. The trick to feeding Zebra Danio fry is finding something that is small enough to fit into their mouths. Make sure that you are observing your Zebra Danio fry at meal time to make sure they are eating. You will want to give them roughly the same diet as larger Zebra Danio with the only difference being in the size of the food that they are being fed.

Zebra Danio Disease

Zebra Danios are considered hardy fish, and this is often the reason that they are chosen by first time aquarists. There are not a lot of ailments that can affect Zebra Danios in general, but they are still susceptible to sickness if they are kept in an unclean environment. It is important for the health and happiness of the Zebra Danio that they are kept in clean, properly maintained water parameters. You can make sure that your fish are being kept properly by performing regular water changes to their tank as well as establishing a cleaning routine.

Zebra Danio are susceptible to an illness called Mycobacteriosis. This illness is caused by microorganisms in the water. Mycobacteriosis will show up as enlarged pores on the skin of the fish, and even missing fins. There is a treatment if caught early enough, but it is not a sure thing. If you suspect that your Zebra Danios are infected with Mycobacteriosis, you will want to quarantine and treat any affected fish as well as clean out their tank thoroughly. Make sure that you wear protective gear and do not have any open wounds on you as this illness is easily spread to humans.

Zebra Danio Tank Mates

Zebra Danios are considered peaceful fish that do well in most community setups.

Zebra Danio and Goldfish

Zebra Danios can make for great tank mates for Goldfish. They both enjoy roughly the same water parameter requirements and similar diets. However, Zebra Danios are much smaller than adult Goldfish. It is possible that if they can catch the speedy Zebra Danios they will eat them. Owners of both Zebra Danios and Goldfish say that they can be housed together as long as they are provided with enough room, and their needs are being met.

Zebra Danio and Betta

It has been said that under the right conditions both Zebra Danios and Bettas could be potential tank mates, but there are a few reasons why they do not do well when kept together in a community setup.

Zebra Danios are quick moving, and are fin-nipping fish. They often will dart around to nip at the slower moving Betta’s tail, and dart away before the Betta can do anything to protect itself. Both fish have rather large appetites, and they will more than likely begin to become aggressive with one another during feeding time. Zebra Danios are quick swimmers, and all their schooling activity could potentially stress out a Betta Fish.

Zebra Danio and Neon Tetra

Neon Tetras are one of the best tank mates to house with Zebra Danio in a community setup. Both species of fish enjoy roughly the same diet, social behaviors, and water parameters. This makes it easy to make sure that the needs of both species are being met.

Zebra Danio and Guppies

Zebra Danios and Guppies can be good tank mates, but it is possible that Zebra Danios will eat small guppies. It is always best to observe any new fish that you introduce into your community setup. This way you can correct any issues as they arise.

Where Can I Find Zebra Danio For Sale?

If you are looking to purchase Zebra Danio for yourself, you will be able to find them in most pet stores, and from breeders online. You can expect to pay around $1 to $3 per Zebra Danio.

Longfin Zebra Danios VS Zebra Danio

Longfin Zebra Danios are not a naturally occurring type of Zebra Danio in the wild. They are all captive bred for their longer flowy fins. The flowy fins of the Longfin Zebra Danio are up to three times the length of the body of the fish.