Emerald Dwarf Rasbora
Microdevario nana
The Emerald Dwarf Rasbora (Microdevario nana) is a peaceful fish that's easy to keep. Give it a tank of at least 40 litres (11 US gallons), water held at 72-81°F, and a pH of 6-7.5. Always keep a group of at least 8 - they feel safest in numbers.
Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.
Natural distribution
Southeast Asia
- East & Southeast Asia
Regional colours match the stocking calculator's origin map.
Emerald Dwarf Rasbora Tank Setup
Give them a tank of at least 40 litres (11 US gallons). As open-water swimmers they care more about swimming length than height, so a longer tank is ideal. Keep the water at 72-81°F with a pH around 6-7.5, and avoid sudden swings. Always keep a group of at least 8 of their own kind - kept alone or in pairs they tend to turn shy, nippy, or wash out in colour.
What Do Emerald Dwarf Rasboras Eat?
They have small mouths, so stick to small foods: crushed flake, fine granules, and now and then a treat of frozen or live foods such as daphnia or baby brine shrimp. Anything too large simply gets ignored.
Emerald Dwarf Rasbora Tank Mates
Vivid green nano rasbora. Keep in groups of 8+. Active and hardy. The Emerald Dwarf Rasbora is peaceful, which is the first thing to weigh up when you choose tank mates. It's a shoaling fish, so settle a group of 8 or more of its own kind before adding anything else - a stressed, lonely fish is far more likely to nip or hide. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.
Are Emerald Dwarf Rasboras Good for Beginners?
Often recommended to beginners, but only after the tank is cycled and you can keep a proper school - not three fish in a new setup.
Emerald Dwarf Rasbora - frequently asked questions
What size tank do Emerald Dwarf Rasboras need?
Emerald Dwarf Rasboras need a tank of at least 40 litres (11 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.
How many Emerald Dwarf Rasboras should I keep together?
Keep a group of at least 8. Emerald Dwarf Rasboras are a shoaling species and become stressed, lose their colour, or hide when kept singly or in pairs.
What water parameters do Emerald Dwarf Rasboras need?
Keep them at 72-81°F with a pH of 6-7.5, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.
What do Emerald Dwarf Rasboras eat?
Emerald Dwarf Rasboras have small mouths, so they need small foods. Crushed flake and fine granules form the staple, with the occasional treat of frozen or live foods such as daphnia or baby brine shrimp. Feed small amounts once or twice a day, and remove anything they don't eat.
Are Emerald Dwarf Rasboras good for beginners?
Yes - Emerald Dwarf Rasboras are a good beginner choice once the tank is fully cycled and you can keep a proper group. They are hardy but still need stable water and a school to feel secure.
Common mistakes with Emerald Dwarf Rasboras
- Buying fewer than 8 - Emerald Dwarf Rasboras need a proper school to feel secure; isolated individuals hide, fail to colour up, or become stressed.
Building a community? Run the full list through the stocking calculator before you add anything else.
Great tank mates
Chosen from temperament, overlapping temperature/pH bands, plausible minimum tank footprints, and size versus yours in App-aquatic data. Hobby nuance always wins - verify stocking and temperament before purchasing.
Fish to avoid mixing with Emerald Dwarf Rasboras
These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.
- OscarPredator - Oscar will eat or injure smaller tank mates
- Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
- Betta (Male)Predator - Betta (Male) will eat or injure smaller tank mates
