In today’s blog, we are going to talk about the Danio. There are many different types, but this article will focus on the positives. However, I will also discuss why the Zebra Danio is sometimes not the best fish for beginners. I hope you enjoy the read. I appreciate you being here.

 

Species Profile

This tank setup features Zebra Danios and was created by Shelby at Garden of Eater. This was a great aquascape that she did at the Keystone Clash, so I definitely appreciate being able to use this tank.

For our species profile, these are the Zebra Danios. Many of the points discussed here apply to other smaller Danio species, which include various types. It’s not just the Zebra Danios — you’ve got the Leopard Danios, long fins, albinos, golden, the Glofish Danio, the Pearl Danio, as well as others.

These fish come from India, but most of the fish you’re going to see in the aquarium hobby are tank-bred. They are usually considered beginner fish. While that’s partially true, I’ll also explain why they may not be the best choice for brand-new fish keepers.

The key points about Zebra Danios

Category	Details
Species	Zebra Danios (Danio rerio), along with other types such as Leopard Danios, Longfin, Albinos, Goldens, Glofish, and Pearl Danios.
Origin	Native to India, but most aquarium specimens are tank-bred.
Size	Typically grow to about 1.5 inches (females slightly larger).
Coloration	Silver and blue stripe pattern, vibrant colors for both males and females.
Temperament	Generally peaceful but can be fin-nippers, especially with long-finned fish.
Tank Requirements	– Minimum Group Size: 6, ideally 10-15. – Tank Size: 10 gallons (bare minimum), 20 gallons recommended. – Substrate: Gravel or sand, darker is preferred.
Water Parameters	– Temperature: 76-78°F (upper 60s to upper 70s acceptable). – pH: 6.8-8.0. – Hardness: 5-15 dGH (around 10 is ideal).
Tank Mates	Good options: Dwarf Gouramis, Peacock Gudgeons, Cherry Barbs, Rasboras, Tetras, Corydoras, Mollies, Swordtails. Avoid long-finned fish.
Breeding	– Egg scatterers. – Require larger gravel or marbles to protect eggs. – Fry need pulverized flakes or baby brine shrimp.
Feeding	Prefer Northfin community flakes, cichlid food, live baby brine shrimp, and other high-quality fish foods.
Activity Level	Very active, swim in mid-water and top-water. Need open swimming space.
Scientific Importance	Used in genetics, development, and cancer research as a model organism.

Size and Appearance

Size-wise, they’re great. As you can see, they top out at around an inch and a half. The females are slightly larger and rounder.

The coloration is impressive for both males and females. They have silver and blue stripes, which is why many people are drawn to them. The long fin varieties are especially beautiful.

Behavior and Temperament

Here’s why they might not be the best choice for new fish keepers, especially those setting up a community tank. While they’re somewhat peaceful, they’re not entirely community fish. Zebra Danios may exhibit fin-nipping behavior.

If you have other fish with long fins, the Danios may nip at them. They can also be rough with each other, so it’s something to consider.

I recommend Zebra Danios for people who have kept fish before and want something active. These fish swim all over the tank — mid-water, top-water — always on the move.

Breeding Zebra Danios

Zebra Danios are relatively easy to breed, as they are egg scatterers.

Option 1: Place larger gravel, pebbles, or marbles at the bottom of the tank. When the males and females spawn, the eggs will fall into the substrate. Be sure to remove the adults immediately, as they will eat the eggs.

Option 2: Use a breeder box with a large mesh. Let the eggs fall through into the main tank, then remove the adults.

The fry usually hatch in a few days. Start feeding them pulverized flake food or North Fin fry food. Once they’re bigger, switch to live baby brine shrimp.

Tank Mates

If you’re keeping Zebra Danios in a community tank, there are some good options. The most important thing is to keep them in decent-sized groups—at least six, but 10-12 or even 15 would be better. This reduces aggression among the group.

If you’re looking for tank mates, you can consider:

• Dwarf Gouramis
• Peacock Gudgeons
• Cherry Barbs
• Larger Rasboras (like Brilliant Green Rasbora)
• Bottom dwellers (like Corydoras or smaller Loaches)
• Livebearers (like Mollies and Swordtails)
• Tetras (like Neon Tetras or Rummy Nose Tetras)
• Dwarf Cichlids (like Apistogramma)

Just avoid long-finned fish, as the Zebra Danios might nip at them.

We will also have species profiles of potential tank mates down in the description below.

Water Parameters

Zebra Danios are often considered beginner fish because they can tolerate a wide range of water parameters. For temperature, they do well anywhere from the upper 60s to the upper 70s. I prefer to keep them around 76 to 78°F. However, if you have an unheated tank and the room stays in the low 70s, you could get away without a heater.

For pH, they can tolerate a range from about 6.8 to 8.0. We keep ours closer to an 8. Water hardness should be between 5 and 15 dGH, and we’re right at about 10 dGH and KH.

If you’re not familiar with water hardness, check out our video on how water hardness impacts fish health. Water quality needs to be good—no ammonia or nitrites, and nitrates should be below 20 parts per million, if possible.

Feeding

Feeding Zebra Danios is straightforward. We use a variety of Northfin Foods, such as Community, Cichlid, Kelp, and Wafer flakes. They also love live baby brine shrimp.

If you want to maximize fish health through food, check out our video on the best fish food combinations.

Tank Size

Many sources recommend a 10-gallon tank for a small group of Zebra Danios, and while this is feasible, I personally prefer a larger tank. A group of 6-7 should do fine in a 10-gallon tank, but I prefer to keep them in at least a 20-gallon tank. This gives them more space and allows me to keep them in larger groups (10-15), which reduces aggression.

When decorating your tank, substrate can be either gravel or sand, though I prefer a darker substrate and background. This really makes their colors pop.

For breeding purposes, larger gravel may work better, but if you don’t plan on breeding them, either substrate is fine. Just make sure to give them plenty of swimming space.

Flow and Tank Setup

Zebra Danios enjoy a moderate flow, so make sure your tank has some current. Keep in mind that higher flow can be challenging for slower fish, and avoid long-finned fish due to fin-nipping.

Breeding

Breeding Zebra Danios is relatively straightforward. You’ll need both males and females, as they are egg scatterers. There are two effective methods to encourage breeding.

Method #1: Use larger gravel or marbles at the bottom of the aquarium. Ensure you have mature males and females, as they usually spawn every couple of days. The eggs will fall into the substrate, and you must remove the adults right away, as they will eat the eggs.

Once the fry hatch, you can feed them pulverized flake food or baby brine shrimp once they’re large enough.

Method #2: You can also place the adults in a breeder box, allowing the eggs to fall through the mesh. Once the fry hatch, move them into a separate tank.

Conclusion

Zebra Danios are active, colorful fish with lots of personality. While they suit intermediate fish keepers, new aquarists should be cautious about their fin-nipping habits and need for a cycled tank.

By keeping them in larger groups and choosing the right tank mates, you can create a beautiful, thriving aquarium.