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Harlequin rasbora, Trigonostigma heteromorpha

Rasboras & danios · Trigonostigma

Harlequin rasbora

Trigonostigma heteromorpha · Peat swamp streams, Malay Peninsula and Sumatra

Photo: NasserHalaweh, CC BY-SA 4.0, via Wikimedia Commons

The Harlequin rasbora (Trigonostigma heteromorpha) is a freshwater fish from Peat swamp streams, Malay Peninsula and Sumatra, where it lives in swamp or paddy habitat. Adults reach about 4.5 cm (1.8 in). Keep it at 22–28 °C (72–82 °F) and pH 5–7.5, in calm water. It is peaceful and does best in a group of 8 or more. It eats most foods: flakes, small pellets and frozen foods.

At a glance

Water temperature

22–28 °C 72–82 °F

pH

5–7.5 soft, acidic water

Adult size

4.5 cm 1.8 in

Swims

Mid-water mostly in open water

Keep together

8 or more a shoal feels safe

Current

Calm still or slow water

Food

Eats most foods

Temperament

Peaceful

≈ Every value here is an estimate from typical hobby ranges. We're checking them against sources.

Where it comes from

Home water

Peat swamp streams, Malay Peninsula and Sumatra

Lives in swamp or paddy habitat.

The dot marks where it's collected. Home from iNaturalist native sightings (55). Map: Natural Earth.

Tank mates

Checked against a roomy 300 L planted tank with low flow and plenty of caves. Your own tank may change the answer: try it in Your tanks.

In the hobby

In stock now

Not in stock at any store we track.

Tanks with this fish

No shared tanks have this fish yet. Share yours from Your tanks.

From keepers

Notes appear here when a keeper shares a tank with this fish and writes about it.

Questions keepers ask

How big does a Harlequin rasbora get?

About 4.5 cm (1.8 in) as an adult.

What temperature does a Harlequin rasbora need?

22–28 °C (72–82 °F).

What pH does a Harlequin rasbora need?

pH 5–7.5.

Does a Harlequin rasbora need to be kept in a group?

Yes. Keep at least 8.

Is the Harlequin rasbora aggressive?

No. It is peaceful with fish that suit the same water.

What does a Harlequin rasbora eat?

It eats most foods: flakes, small pellets and frozen foods.

Where does the Harlequin rasbora come from?

Peat swamp streams, Malay Peninsula and Sumatra.

What fish can live with a Harlequin rasbora?

Good tank mates include Candy stripe (L015), Leopard frog (L134), Amano shrimp, Boeseman's rainbowfish, Bolivian ram.

All the numbers

Temperature min (°C)22 Estimate
Temperature max (°C)28 Estimate
pH min5 Estimate
pH max7.5 Estimate
Adult size (cm)4.5 Estimate
FlowLow Estimate
Habitatswamp Estimate
Smallest happy group8 Estimate
TemperamentPeaceful Estimate
DietOmnivore Estimate
Typical price min (CAD)3 Estimate
Typical price max (CAD)5 Estimate

Some values are estimates from typical hobby ranges and haven't been checked against a source yet.