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Everything You Need to Know About Danios

Danios are one of the most popular freshwater fish for several good reasons. They are inexpensive, hardy, and very active fish. Beginning fish keepers looking for small fish that are easy to breed will find danios to be a great addition to any community tank. With a little effort they may even be fortunate enough to see their danios lay eggs.

Everything You Need to Know About Danios

What are Danios?

Danios are schooling fish in the family Cyprinidae, a large group of fish that also includes goldfish, barbs, rasboras, and koi carp. Cyprinids are known as “true minnows” so calling any small fish a minnow is incorrect.

All danio fish are found in South and southeast Asia. India, Myannmar, and Pakistan are where many aquarium fish are found.

In their natural habitat wild danios are schooling fish that live in huge groups. Their colors and danio size depends on the species in question. There are dozens of different danio types. But only a few are raised in fish farms.

  • Common Names: Zebra Danio, Giant Danio, Leopard Danio, Galaxy Rasbora, etc
  • Scientific Name: family Cyprinidae
  • Origin: South and Southeast Asia
  • Length: Most are 1 to 2 inches long when full grown
  • Aquarium Size: 10 to 20 gallons
  • Temperament: Peaceful; Schooling
  • Ease of Care: Very Easy

Types of Danios

You may see different danios for sale in pet stores at times. But these are by far the most common danio fish to find.

Zebra Danio

Zebra Danio
Fishkeeping World

Zebra danios (Danio rerio) are by far the most popular in the aquarium industry. They have distinct horizontal stripes of blue and gold. And as community fish they have a peaceful nature. Zebra danios grow no larger than 2 inches. Longfin zebra danio, leopard danios, and other color morphs are also common in the aquarium trade.

Giant Danio

Giant Danio

Giant danios (Devario aequipinnatus) live up to their name. Giant danio fish size is as long as 4 inches. And just like most danios Giant danios are active fish that need a spacious aquarium. A group of 6 or more should be kept in a tank size no smaller than 40 gallons. Giant danios are popular dither fish for large or aggressive tank mates like cichlids.

Pearl Danio

Pearl Danio

Pearl danios are a small species of freshwater fish, never growing larger than 1.5 inches. Like Zebra danios the Pearl danio is a peaceful community tank resident and easy to care for.

Celestial Pearl Danio

Celestial Pearl Danio
Fishkeeping World

The Celestial Pearl danio is a newer species that has become quite popular with planted aquarists. It is hardy but needs a water temperature lower than most tropical fish because its natural habitat is cool and mountainous. As shoaling fish Celestial Pearl danios tolerate each other. But the males are a little territorial at times.

Caring for Danio Fish

Danios of all kinds are very hardy fish that don’t need much care to live their best life. Danios do well in aquariums with plants. Live plants provide oxygen, shade, and use ammonia and other pollutants as fertilizer.

And when your zebra danios spawn they scatter their eggs in tangles of bushy plants like Hornwort or Guppy Grass. Some may nibble on softer plants. But as long as you offer enough food your danios will leave your live plants alone.

What Size Tank Do Danios Need?

Most danios are not large fish but they are quite active. So their tank requirements are a little larger than you’d expect for fish their size. Six to ten danios in a 10 gallon tank is a good number so long as there are not too many other fish.

What Size Tank Do Danios Need?

For larger species like the giant danio you need at least 40 gallon aquariums for a group of six or more. A larger tank size will provides zebra danios with space but also ensures that he tank remains uncrowded.

That way water quality remains pristine. Smaller, more crowded tanks become polluted much faster and require more maintenance to maintain good water quality.

A secure lid is important because danios not only swim fast but sometimes jump if startled. A large or aggressive fish may cause your danios to try fleeing by leaping.

Water Conditions for Danios Freshwater Fish

Danio fish of most species prefer cooler temperatures than other tropical fish to thrive. 70-78°F is best for them, with the warmer levels better for a breeding tank.

Good filtration is important because wild danios come from fast flowing streams. The water parameters should include high oxygen levels as a result.

Allowing the outflow of your filter to splash or setting up a bubble curtain as an aerator will help keep oxygen levels high. A cooler water temperature also keeps oxygen in solution for your zebra danios.

The pH of your aquarium is not super important; just avoid extremes in chemistry. The closer to neutral (pH 7.0) you achieve the better. But slight alkaline or acidic water chemistry is fine for danios.

Driftwood and sedimentary rocks should either be absent or added in small pieces. Both of these decorations cause the pH to either rise or fall so stick to items that don’t impact water quality too much.

Tap water in most countries tends to be a little alkaline (pH 7.0+). Danios prefer neutral chemistry but most species are fine with alkaline conditions and will still breed for you in hard water. Wild caught danios are pickier, however.

Feeding Danios

As omnivores it is quite easy to feed danios. In nature they eat small insects, water fleas, worms, mosquito larvae, and other small invertebrates.

I also recommend offering frozen foods to give your danios a nutritional boost. Frozen foods offer extra protein, fat, and color-enhancing pigments like carotenoids and astaxanthin. Many fish show enhanced tones when fed red and orange foods like brine shrimp and blood worms. The extra nutrition is also important if you want to breed your danios.

And prepared food should be small enough to fit in their tiny mouths. Micro pellet formulas are ideal since they don’t cloud the water and will soften when added to water.

Live foods can be fun for you to offer but aren’t required. Like frozen food they are very nutritious for aquarium fish and are a good treat to provide sometimes.

Danios Fish Tank Mates

The best tank mates are peaceful community fish. Most fish found in your local pet store will be a good match since zebra danios are very gentle neighbors.

Danios Fish Tank Mates

Here are a few community tank mates guaranteed to live well with danios:

That said, there are dozens of fish that will also live with danios. Be careful with Betta fish. Their long fins can be tempting targets. Danios are sometimes nippers and will nibble tank mates with flowing fins, causing infection and even fin loss.

How Do I Breed Danio Fish?

As long as they have a clean tank and good food danios spawn on the regular. You will see a female danio fat with eggs often enough.

But if you want to raise the fry you need to set up a breeding tank. Zebra danios eat their eggs and fry after spawning. So you should remove the parents once they have spawned. You will see your danios spawn in most aquariums, however.

Danio fry are quite small and need infusoria and other fine sized fry food. After the first 1 to 2 weeks they will be large enough to eat live brine shrimp nauplii.

Live foods are important for the young fry because they respond to movement when they hatch. It will take a few weeks before the young danio fry will eat powdered flake food and other prepared blends.


Zebra danios and their relatives are small aquarium fish with bright colors and plenty of energy. They are not at all difficult to care for and feed on anything aquarists offer them. So long as you watch the water temperature and keep oxygen levels high danios are sure to thrive in your aquarium.

More Frequently Asked Questions About Danio Fish

Still interested in learning more about zebra danio care? Then here are a few frequently asked questions I get about how to care for different danios.

Are Danio Fish Easy to Take Care Of?

Danios are some of the easiest pet fish to keep that you will ever own. Zebra danios feed on anything that is offered to them. And they are not at all picky when it comes to water quality or parameters in your aquarium.

Are Danios Schooling Fish?

Zebra danios and other danio fish are schooling fish. So they should be kept in groups no smaller than six individuals. And more of their own kind is better for them.

How Big Do Danios Get?

Most danios will not grow larger than 2 inches, except for the Giant danio, which reaches up to 4 inches. The Galaxy Rasbora or Celestial Pearl danio is a true nano fish and never grows much larger than 1 inch.

Are Danios Aggressive Fish?

All danios are peaceful fish and get along well with other community tank mates. They are sometimes fin nippers, however. So watch them when keeping them alongside bettas, fancy guppies, and other long-finned fish.

Jason Roberts
About Jason Roberts
Jason is an aquarium fanatic that has been a fish hobbyist for almost three decades.