Zebra Danio

Danio rerio

Also known as: Zebrafish, Zebra fish, Danio rerio

Water Parameters

• Temperature: 18–25°C
• pH: 6–8
• Hardness: 80–357 ppm

Care Summary

Among the hardiest aquarium fish in the hobby — famously resilient, widely used as scientific model organisms, and tolerant of a broader range of parameters than nearly any other community species. Schools tightly and swims constantly across the upper two-thirds of the water column. Strikingly attractive in numbers, with horizontal blue-and-silver stripes that flash as the school turns. Increasingly available in glowing GloFish varieties (genetically modified for fluorescence) — these are the same species and have identical care requirements, though some jurisdictions restrict their sale.

Tankmates

Active and constantly moving — best kept in groups of at least 6, ideally 10+, in a tank with plenty of horizontal swimming space. The constant darting motion makes them poor tankmates for slow or long-finned species like bettas, fancy guppies, and angelfish; they will nip flowing fins out of excitement rather than aggression. Excellent companions for other active community species. One of the few popular community fish that genuinely thrives at room temperature without a heater, making them useful for unheated tanks.

Compatible with

• Bronze Corydoras
• Harlequin Rasbora
• White Cloud Mountain Minnow
• Otocinclus
• Kuhli Loach
• Bristlenose Pleco

Avoid keeping with

• Betta
• Long Finned Species
• Angelfish Adult
• Fancy Guppy

Common Problems

• fin nipping of slow tankmates
• stress and reduced schooling in groups smaller than 6
• occasional ich
• boredom and aggression in cramped tanks

Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-06