Not furry, but we like them anyway.

Emerald Dwarf Rasbora

Danio erythromicron

Also called Emerald dwarf danio, Cross-banded dwarf rasbora, Celestichthys erythromicron, Microrasbora erythromicron (former name)

SpeciesShort profile

From Endemic to Inle Lake and its surrounding watershed in Shan State, Myanmar, with populations also near Loikaw in Kayah State1 2 3

At a glance the quick version

Length2 to 3 cm1 2

Sizesmall

Unusual barred pattern for a tiny fish

Fits small planted aquariums

Interesting to watch in a group

Looks how to spot one

Tiny, compact cyprinid

A miniature fish with a row of vertical bars down its sides that shimmer iridescent blue to green. The fins show red tones. Males are the more vivid sex with bright blue bars and red fins, while females are slightly larger and rounder.1

Coloursiridescent blue-green vertical barsred-toned finswarm body tones1

Personality what they are like

A timid shoaling fish that prefers calm company. Males spar briefly with each other, which is spread out in a larger group.1

Daily activity how busy a day looks

Spends its time weaving through thick plants and roots. It prefers peaceful conditions over fast flow.1

Grooming and care the hands-on bits

Keep water stable and on the hard, alkaline side, offer a varied diet of small foods, and provide dense planting for cover.1

Home where they are happiest

Clear, hard, neutral to slightly alkaline water at about 20 to 24 C, pH roughly 7.0 to 8.0 and hardness 12 to 20 dGH. A base of at least 60 x 30 cm (about 54 litres). Its home lake is clear, shallow and lined with dense plants and floating gardens.1 2

Food basics what goes in the bowl

Feeds on tiny invertebrates, algae and zooplankton. Offer small live and frozen foods such as Daphnia and brine shrimp alongside small dry food.1 2

Company who they like around

Best in a group of 20 or more with other tiny, calm fish. Keep it apart from the Celestial Pearl Danio as the two can crossbreed.1

The story where it all began

Described by Annandale in 1918 from Inle Lake, a high karst lake in Myanmar, and first named Microrasbora erythromicron. Later studies moved it to Danio (some authors use Celestichthys). Its closest relatives are the Celestial Pearl Danio and Danio choprai.1 3

Fun facts for the dinner table

1
Its home, Inle Lake, sits about 900 m above sea level and is mostly only 2 to 3 m deep.1
2
It shelters among the roots of the lake's famous floating garden islands.1
3
Females lay around 30 slightly sticky eggs per spawning, which hatch in about 72 hours.1
4
Its closest living relatives are the Celestial Pearl Danio and Danio choprai.3

Recognised by the official bits

IUCN Red List: Endangered (assessed February 2011)2

The care rhythm a typical week and year

A typical home-care rhythm for an Emerald Dwarf Rasbora. A starting point, not a vet's advice.

FeedingSmall amounts once or twice a dayevery day
Temperature checkevery day
Water changeAbout 25% of the waterevery week
Water testevery week
Glass cleanevery week
Filter rinseRinse in old tank water, never tap waterevery month

Owner questions the things everyone asks

How often should I feed my Emerald Dwarf Rasbora?

Feed your Emerald Dwarf Rasbora small amounts once or twice daily. Furry Diary's starting plan suggests a daily feeding schedule. Offer a variety of tiny live, frozen and dry foods to keep it healthy.1 2 Pet Wiki plan

What does an Emerald Dwarf Rasbora eat, and what should it never eat?

This tiny fish enjoys small live and frozen foods like Daphnia and brine shrimp, plus fine dry food. It also nibbles on algae and zooplankton. For foods to avoid, please ask a vet or experienced breeder, as the input doesn't list any.1 2

How much space does an Emerald Dwarf Rasbora need?

Your Emerald Dwarf Rasbora needs a tank with a base of at least 60 x 30 cm, which is about 54 litres. This gives it room to swim and shoal comfortably.1 2

What temperature, light or water does an Emerald Dwarf Rasbora need?

Keep the water clear, hard and neutral to slightly alkaline: temperature 20, 24°C, pH 7.0, 8.0, hardness 12, 20 dGH. Provide dense planting and gentle lighting, as it comes from a clear, shallow lake with floating gardens.1 2

How often should I clean an Emerald Dwarf Rasbora's home?

Furry Diary's plan recommends a weekly 25% water change and glass cleaning, plus a monthly filter rinse using old tank water. This keeps the water stable and your fish happy. Pet Wiki plan

Can an Emerald Dwarf Rasbora live with others?

Yes, it's a peaceful shoaling fish that thrives in a group of 20 or more with other tiny, calm species. Avoid keeping it with Celestial Pearl Danios, as they can crossbreed.1

How long does an Emerald Dwarf Rasbora live?

Lifespan varies depending on care and environment. For a reliable estimate, please ask a vet or a good breeder who knows this species well.

Can I handle an Emerald Dwarf Rasbora?

This tiny, timid fish is not meant to be handled, it stresses easily and is very delicate. Enjoy watching it weave through plants instead of touching it.1

Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.

Celestial Pearl Danio

Neon Green Rasbora

Where this comes from

Every fact on this page has a numbered source. Spotted an error? support@petwiki.app.

Celestichthys erythromicron, Seriously Fish seriouslyfish.comused for names, origin, habitat, size, water parameters, tank size, diet, behaviour, colours, history, fun facts
Danio erythromicron, FishBase fishbase.seused for max length, IUCN status, distribution, water parameters
Danio erythromicron, Wikipedia en.wikipedia.orgused for other names, origin, taxonomy, relatives

Checked 2026-09-30. Text is written in our own words from these sources.