Zebra Danio (Danio rerio)

The Zebra Danio (Danio rerio) is one of the most iconic and widely kept aquarium fish in the world, and one of the best-studied vertebrates in biological science. Native to the shallow streams, rice paddies, and seasonal ponds of South Asia (India, Bangladesh, Nepal, and surrounding countries), it is characterized by its distinctive horizontal blue-silver stripes running from gill to tail on a streamlined, torpedo-shaped body.

Zebra Danios are among the most recommended beginner fish for several excellent reasons: they are exceptionally hardy, tolerating a wide range of water conditions and temperatures; they are active and entertaining schooling fish; they are peaceful with all other community fish; and they are very easy to feed. Their tireless swimming activity brings life and movement to any aquarium.

They are fast, active fish that occupy all levels of the water column but particularly enjoy open mid-water and surface swimming. They must be kept in schools of 8 or more for best behavior and reduced stress. Various captive-bred varieties are available including the long-finned variety, GloFish (fluorescent transgenic varieties), and leopard (spotted) pattern.

Zebra Danios are egg-scatterers that spawn readily in fine-leaved plants or over marbles. They are prolific, though adults will eat eggs if not removed.

Water Parameters: Extremely adaptable: pH 6.5–7.5, temperature 18–26°C, GH 5–20. Can survive temperatures as low as 15°C and as high as 30°C temporarily, though 18–24°C is optimal. One of the most temperature-tolerant tropical fish. Tolerates a wide range of hardness.

Tank Setup: Minimum 60 liters for a school of 8. Open swimming space is most important. Fine gravel or sand substrate. Plants along borders and back of tank. Good filtration with moderate current. SECURE LID — Zebra Danios are impressive jumpers.

Feeding: Omnivores that accept virtually any food: flake food, pellets, frozen bloodworm, daphnia, brine shrimp. Feed twice daily. Not fussy — one of the easiest fish to feed.

Tankmates: Compatible with virtually all peaceful community fish of appropriate size. Excellent with other danios, tetras, rasboras, barbs, corydoras, and small gouramis. Their active nature can stress very slow or docile fish — pair accordingly.

Health: One of the hardiest aquarium fish. Rarely sick in good conditions. Watch for ich with sudden temperature drops. Avoid fin-nipping species with long-finned varieties. Regular 25% weekly water changes maintain optimal health.