Emerald Dwarf Rasbora
Danio erythromicron
Also sold as EDR · Emerald dwarf danio
Synonyms Emerald rasbora · Microrasbora erythromicron
Emerald Dwarf Rasbora (Danio erythromicron) is a peaceful freshwater fish that reaches about 2 cm (0.8 in) and swims along the bottom in a shoal. It wants 68–79°F (20–26°C) and pH 7–8, is kept in groups of 8 or more, and needs a tank of at least 40 L (11 gal).
At a glance
| Type | Fish |
|---|---|
| Adult size | 2 cm (0.8 in) |
| Minimum tank | 40 L (11 gal) |
| Group size | 8 or more |
| Temperature | 68–79°F (20–26°C) |
| pH | 7–8 |
| Temperament | Peaceful |
| GH | 5–15 |
| Lifespan | 3–5 years |
| Eats shrimp | Shrimplets only |
Before it goes in
- Emerald Dwarf Rasbora needs at least 40 L (11 gal). The smallest size in this library that clears that is the 15 Gallon.
- Keep 8 or more. Below that it hides, colours down and is far more likely to be picked on.
- Adult shrimp are safe; shrimplets will be eaten, so a shrimp colony will not grow in the same tank.
- It holds at 68–79°F (20–26°C). That shares a window with Betta and Cherry Shrimp, but not with Discus.
- A group of 8 takes up roughly 24% of what a 15 Gallon will comfortably hold, so plan the rest of the stock around it.
What tank size does it need?
At least 40 L (11 gal). The smallest size here that clears it is the 15 Gallon.
How many should I keep?
8 or more. Fewer than that and it spends its time hiding instead of out in the open.
Will it eat shrimp?
Adults are safe, shrimplets are not. You can keep shrimp with it; you just will not get a growing colony.
What water does it want?
68–79°F (20–26°C), pH 7–8, GH 5–15.
How long does it live?
3–5 years in a tank that suits it. That is how long you are signing up for.
Good tank mates
- Tank mates from this library that share its temperature window, are peaceful and eat neither it nor its young: Cherry Shrimp, Goldfish, Bristlenose Pleco, Celestial Pearl Danio and Molly.
- Plants that hold up with it: Hygrophila corymbosa 'Siamensis', Water Sprite, Anubias nana 'Petite' and Cryptocoryne wendtii.
Often compared with
| Emerald Dwarf Rasbora | Celestial Pearl Danio | Zebra Danio | |
|---|---|---|---|
| Adult size | 2 cm | 2.5 cm | 5 cm |
| Min tank | 40 L | 40 L | 60 L |
| Group | 8+ | 8+ | 6+ |
| Temperature | 68–79°F (20–26°C) | 68–79°F (20–26°C) | 64–79°F (18–26°C) |
| Eats shrimp | Shrimplets only | Shrimplets only | Shrimplets only |
More livestock
Sources (4) · checked Sep 2026
- What it eats, Mature tanktheshrimpfarm.com
- What it eatsaquaticarts.com
- Mature tanktheshrimpfarm.com
- aquariumsource.com