Zebra Danio Care: The Toughest Little River Fish

If there's one fish that was born for a river tank, it's the zebra danio. It's small, cheap and nearly indestructible. It schools, it's always in motion, and it will happily swim straight into the current all day long like it's training for something.

The basics

• Scientific name: Danio rerio
• Size: about 2 inches
• Lifespan: several years with good care
• From: streams, rice paddies and floodplains in South Asia
• Price: usually a few dollars each

Why they fit a river tank

Zebra danios love moving, oxygen-rich water. In a tank with a good river manifold, they'll gather up at the head of the current and swim into it, then drift back and do it again. They also tolerate a wide range of temperatures, which makes them a good choice for cooler river tanks.

Setting them up

• Group size: six or more. A bigger group is better. In small numbers they get stressed and nippy.
• Tank: 10 gallons can work for a small group, but they're fast swimmers that use a long tank well. A 55-gallon long is perfect.
• Temperature: they're comfortable from the mid-60s to the upper 70s °F.
• A tight lid. Danios jump.
• Open swimming space along the top and middle of the tank, with plants and rocks around the edges.

Feeding

Easy. Flakes, small pellets, and frozen or live foods like brine shrimp and daphnia. They feed at the top and middle, so the food often doesn't reach the bottom. Make sure your bottom feeders get their own food.

Tankmates

Good with other active, similar-sized fish: White Cloud minnows, other danios, rasboras, barbs, hillstream loaches, bristlenose plecos and corydoras.

Avoid slow fish with long fins, like bettas and fancy guppies. Danios are fast and playful, and their "play" can turn into fin nipping. Avoid fish big enough to eat them.

Varieties

• Long-fin zebras: the same fish with flowing fins. Not quite as fast in strong current.
• Leopard danios: spotted instead of striped.
• GloFish danios: genetically modified to glow red, green, orange, purple or blue under blue light. They're legal to sell in most of the U.S., and they have the same care needs as regular zebras.

Science stars

The zebra danio is also one of the most important lab animals in the world. Scientists use it to study genetics, development and disease, because the embryos are see-through and develop quickly. The fish in your tank is a close cousin to the ones in thousands of research labs.

Breeding

They scatter eggs over plants or gravel, and the adults eat them right away. If you want fry, use a separate tank with marbles or a mesh on the bottom so the eggs fall out of reach.

For more fish that thrive in a current, see best fish for strong-current tanks and our list of underrated river tank fish.

Sources (2)

FishLore: Zebra Danio Care · Seriously Fish: Danio rerio

Photo by Kuznetsov_Peter on Pixabay.

Related: Ten Fish That Thrive Best In A River Tank Style Aquarium (Riparium)