Zebra Danio
Zebra Danio (Danio rerio) is arguably the most famous and widely kept small freshwater fish in the world — and with good reason. The silver body with vivid horizontal blue and silver stripes, the tireless activity, the absolute hardiness, and the ease of breeding have made this fish a cornerstone of the hobby for over a century. It is also one of the most important research organisms in modern biology — more is known about the genetics and development of Danio rerio than almost any other vertebrate.
Feeding & Care Tip: Sera Vipan Tropical Flakes and Hikari Micro Pellets make excellent daily staples. Supplement 2–3× per week with Hikari Frozen or Freeze-Dried Bloodworms or Hikari Vibra Bites to enhance color and condition. Hikari Frozen or Freeze-Dried Baby Brine Shrimp are an excellent additional treat. Feed small amounts 2–3 times daily. A tight-fitting lid is strongly recommended — danios are enthusiastic jumpers.
Native to rice paddies, streams, rivers, and ponds across a vast range — India, Bangladesh, Nepal, Pakistan, Bhutan, and Myanmar. This enormous native range explains the Zebra Danio's extraordinary adaptability to varied water conditions. It is one of the few truly 'bulletproof' aquarium fish, tolerating temperatures from 60–80°F, a wide pH range, and water quality that would stress most tropical fish.
Keep in groups of at least five — Zebra Danios establish a social hierarchy through constant chasing and displaying, and a proper group directs this energy inward. A lone or paired Zebra Danio will fin-nip other fish. In a group of six or more they are almost completely peaceful with all other species. Active dither fish — their bold behavior helps shy fish feel secure.
Danios are prolific and easy egg-scatterers that spawn with little encouragement in a well-maintained aquarium. Males chase females vigorously before spawning among fine-leaved plants or over the substrate. Eggs and fry receive no parental care — adults will eat eggs if given the chance. For intentional breeding, a separate shallow tank with spawning mops or fine-leaved plants, slightly warmer water, and removal of adults after spawning is straightforward and reliable. The Zebra Danio has also been the subject of a genetic modification that introduced fluorescent protein genes — the resulting 'GloFish' strains glow under UV light. Standard wild-type fish are the original and in many ways most beautiful form.
Care & Ideal Parameters
| Difficulty | Easy |
| Temperament | Peaceful — active community dither fish |
| Typical Adult Size | 2.0 inches (5 cm) |
| Min. Group Size | 5 minimum |
| Ideal Temp | 64–79°F (18–26°C) |
| Ideal pH | 6.0–8.0 |
| Ideal GH | 2–20 dGH |
| Ideal KH | 1–12 dKH |
| Staple Food | Sera Vipan Tropical Flakes; Hikari Micro Pellets |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Bloodworms; Hikari Vibra Bites; Hikari Frozen or Freeze-Dried Baby Brine Shrimp |
| Origin | India, Bangladesh, Nepal, Pakistan, Bhutan, Myanmar (captive-bred stock) |
| Notes | One of the most researched vertebrates in biology. Extremely hardy and adaptable. Dither fish — helps shy tankmates. Groups of 5+ essential. Prolific egg-scatterer. Tight-fitting lid required — enthusiastic jumper. |