Not furry, but we like them anyway.

Clown Rasbora

Rasbora kalochroma

Also called Leuciscus kalochroma (former name)

SpeciesShort profile

From Southeast Asia: Peninsular Malaysia, Sumatra and western and southern Borneo, in peat swamp forest blackwaters1 2 3

At a glance the quick version

Length10 cm1 2 3

Sizemedium

Very peaceful community fish

Rich red colour that deepens in tea-coloured water

Striking two-spot pattern

1 3

Looks how to spot one

Slender, scaled cyprinid with a forked tail

A larger rasbora with a pinkish to deep red body. Two dark blotches sit on each flank, one just behind the gill cover and a bigger one in the middle of the body, and their exact shape varies between wild populations. Males tend to be slimmer and brighter, while mature females are larger and rounder.1 3

Colourspinkish to reddish bodydark flank blotchesricher red in males1 3

Personality what they are like

Calm and gentle, but a little shy until it is kept in a proper group. In a settled shoal the males show off their colours to one another, which makes for a lively display.1

Daily activity how busy a day looks

An active swimmer that needs open water along the length of a roomy tank. It is a capable jumper, so a well-fitting lid is important.1

Grooming and care the hands-on bits

Does best in a mature, stable aquarium rather than a newly set up one. Steady water chemistry, regular partial water changes and a tight cover keep it comfortable.1

Home where they are happiest

Soft, acidic to neutral water at about 23 to 28 C, pH roughly 5.0 to 7.5 and hardness 2 to 10 dGH. A base of at least 120 x 45 cm (about 240 litres) suits a group. Dim light, leaf litter, wood and tannin-stained water echo its swamp home and bring out its colour.1 2

Food basics what goes in the bowl

In nature it eats small aquatic and land insects and other invertebrates. In the aquarium it takes good flakes and granules, best mixed with live or frozen bloodworm, Daphnia and brine shrimp.1 2

Company who they like around

A schooling fish that should live in a group of at least 8 to 10. Fits well with other peaceful fish of similar size.1

The story where it all began

First described by Bleeker in 1851 under the name Leuciscus kalochroma and later placed in Rasbora. Its home is the ancient peat swamp forests of Malaysia, Sumatra and Borneo, where tannins stain the water dark. Very similar relatives include Rasbora kottelati, which has an extra spot near the tail.3 1

Fun facts for the dinner table

1
At around 10 cm it is one of the larger rasboras kept in home aquariums.2
2
Its wild home can be as acidic as pH 4, coloured dark by tannins from fallen leaves.1
3
The size and shape of its dark side spots differ from one locality to another.1
4
It scatters its eggs among plants and gives no parental care; in a mature planted tank some fry may grow up unaided.1

Recognised by the official bits

IUCN Red List: Least Concern (assessed August 2019)2
FishBase: Listed as a species used in the aquarium trade2

The care rhythm a typical week and year

A typical home-care rhythm for a Clown 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 Clown Rasbora?

Feed small amounts once or twice a day. Furry Diary's starting plan is to offer food daily, but always check the food label and ask your vet for the exact portion size.1 Pet Wiki plan

What does a Clown Rasbora eat, and what should it never eat?

It enjoys good flakes and granules, plus live or frozen bloodworm, Daphnia and brine shrimp. Avoid any food not meant for fish, and never give medicines or human foods without a vet's advice.1 2

How much space does a Clown Rasbora need?

A group needs a tank base of at least 120 x 45 cm, which is about 240 litres. This gives them room to swim and show their colours.1

What temperature, light or water does a Clown Rasbora need?

Keep water at 23 to 28°C, pH 5.0 to 7.5, and hardness 2 to 10 dGH. Use dim light, leaf litter and wood to create a tannin-stained, swamp-like home.1 2

How often should I clean a Clown Rasbora's home?

Furry Diary's plan suggests a 25% water change every week, along with weekly glass cleaning and water testing. Rinse the filter monthly in old tank water, never tap water. Pet Wiki plan

Can a Clown Rasbora live with others?

Yes, it is a peaceful schooling fish that should live in a group of at least 8 to 10. It gets along well with other peaceful fish of similar size.1

How long does a Clown Rasbora live?

Lifespan varies with care; ask a good breeder or exotic-pet vet for typical expectations in your setup.

Can I handle a Clown Rasbora?

It is best not to handle this fish, as it is delicate and a capable jumper. Use a net only when necessary, and always keep a tight lid on the tank.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.

Harlequin Rasbora

Where this comes from

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

Rasbora kalochroma (Clown Rasbora), Seriously Fish seriouslyfish.comused for origin, habitat, size, water parameters, tank size, diet, behaviour, fun facts
Rasbora kalochroma, FishBase fishbase.seused for max length, IUCN status, distribution, temperature
Clown rasbora, Wikipedia en.wikipedia.orgused for colours, former name, history

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