Furry Diary

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Brilliant Rasbora

Rasbora einthovenii

SpeciesShort profile

From Southeast Asia: southern Thailand, Peninsular Malaysia, Singapore, Sumatra, Bangka and Borneo; peat swamp forests and blackwater streams123

At a glance the quick version

Length9 to 10.6 cm12
Sizemedium

Seriously Fish gives about 9 cm SL and FishBase a maximum of 10.6 cm SL; Wikipedia gives 5 cm for adults

Very peaceful
Glowing colours in blackwater
Good community fish
1

Looks how to spot one

Slender, elongated scaled cyprinid

A slender, elongated rasbora with a pinkish body. A dark band with uneven, crinkly edges runs along the side and continues through and past the eye. Colours look richest in tannin-stained water under soft light. Females are rounder and often larger than males.1

Colourspinkishsilverydark lateral stripe1

Personality what they are like

Very peaceful and easygoing, mixing well with a wide range of small community fish. It is more confident and colourful in a group.1

Daily activity how busy a day looks

An active schooling swimmer that needs a reasonably long tank with swimming space.1

Grooming and care the hands-on bits

Keep the water clean with regular changes. Dim lighting and tannin-stained water bring out its colour.1

Home where they are happiest

A tank of at least 120 x 30 x 30 cm (about 113 litres). Temperature 22-26 °C, pH 5.0-7.5 (FishBase 6.0-6.5), soft water around 2-10 °H. Dark substrate, plants, wood and leaf litter mimic its forest streams.12

Food basics what goes in the bowl

A micropredator feeding on worms, small crustaceans and insects. Offer small live and frozen foods such as Daphnia and Artemia, with dried food as a supplement rather than the only food.12

Company who they like around

Keep at least six together. Good companions are other small cyprinids, tetras, livebearers, dwarf cichlids, catfish and loaches.1

The story where it all began

Pieter Bleeker described this species in 1851. In the wild it lives in forest streams and peat swamp waters across the Malay Peninsula and western Indonesia.21

Fun facts for the dinner table

  1. 1

    Its colours become noticeably more intense in tea-coloured, tannin-rich water.1

  2. 2

    Its dark side stripe runs right through the eye and beyond.1

  3. 3

    In the wild it spawns among thick growths of water plants.2

Recognised by the official bits

IUCN Red List
Assessed as Least Concern (January 2019)2
FishBase
Described by Bleeker in 1851; listed as a commercial aquarium species2

The care rhythm Furry Diary remembers it for you

A typical home-care rhythm for a Brilliant Rasbora. It is our own starting plan, not a vet's advice, and you can change every line in the app.

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Where this comes from

Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.

  1. Seriously Fish - Rasbora einthovenii seriouslyfish.comused for origin, size, tank size, water parameters, diet, behaviour, colour, facts
  2. FishBase - Rasbora einthovenii fishbase.seused for author/year, IUCN status, size, habitat, diet, spawning
  3. Wikipedia - Rasbora einthovenii en.wikipedia.orgused for distribution, alternate adult size

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