Is this fish suitable for beginners?

Yes — Harlequin Rasboras are generally considered beginner-friendly and adapt well to typical aquarium conditions. That said, they're sensitive to sudden water changes, so acclimate them carefully when introducing them to a new tank.

How many should I keep together?

Since they're a schooling species, it's best to keep at least six to ten together. Smaller groups tend to be skittish and spend more time hiding.

Can it be kept with other fish?

Yes, its peaceful temperament makes it a good tankmate for other calm, similarly sized fish. Avoid pairing it with aggressive species or fish that are much larger.

What should I feed it?

Harlequin Rasboras readily eat artificial flake or pellet food as well as frozen food, and aren't fussy eaters. Since their mouths are small, small-sized food fed in modest portions works best.

How big does it grow and how long does it live?

Harlequin Rasboras stay small, reaching about 3 to 4 cm as adults, and typically live around three to five years. Their compact size makes them easy to fit into a modestly sized tank.

Harlequin Rasbora

The Harlequin Rasbora is a small, popular aquarium fish known for its orange body marked with a striking black triangular patch — a look that really pops against a planted tank. Naturally peaceful and social, it forms tight schools with others of its kind, so keeping several together lets you enjoy its schooling behavior at its best. It readily eats both artificial and frozen foods, and its beginner-friendly care makes it a great choice for first-time fishkeepers. Adults stay compact at about 3 to 4 cm and typically live three to five years, making them easy to house alongside other peaceful, similarly sized fish in a well-planted aquarium.

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Harlequin Rasbora key facts

Care level: Beginner-friendly
Lifespan: 3-5 years
Size: 3-4cm
Temperature: 24〜28℃
Diet: Pellets, Frozen food
Water: Slightly acidic to neutral (pH 5.5-7.0)
Water Temperature & Quality: Maintain 24-28°C. Keep the water soft and slightly acidic; a blackwater setup brings out stronger colours.
Housing: Peaceful and sociable, so keep 10 or more. It suits planted tanks well, especially layouts with lush broad-leaved plants.
Tank Mates & Compatibility: A community-tank staple that mixes with many small tropical fish. Pair it with peaceful species of similar size.
Diet & Feeding: Omnivorous, accepting granules, flakes, frozen daphnia and more. Feed in several small portions it can finish.
Breeding & Egg-laying: It spawns on the undersides of broad leaves such as Anubias or Cryptocoryne. Success is more likely in soft, slightly acidic water.

TraitsHarlequinTriangle markSchoolingOrange

About Harlequin Rasbora

The Harlequin Rasbora is a peaceful, beginner-friendly schooling fish with a striking black triangle marking. Grows to about 3-4 cm and lives 3-5 years.

7 things to know before welcoming a Harlequin Rasbora

1Keep them in a school
Kept alone or in twos or threes, Harlequin Rasboras tend to hide and rarely show their natural behavior. Bring home at least six to ten at once so they can form the tight, shimmering schools they're known for.
2Peaceful and community-friendly
Harlequin Rasboras are peaceful and rarely bother other fish, making them a good match for other calm, small tankmates. Avoid housing them with aggressive or much larger fish, which can stress them into hiding.
3Shines in a planted tank
Their orange body and black triangular marking stand out beautifully against a backdrop of green plants. Adding plants and driftwood for cover also helps them feel secure and settle in.
4Feeds on flake and frozen food
They readily eat both flake or pellet food and frozen food, and are not picky eaters. Because their mouths are small, offer small-sized food in a few light feedings throughout the day.
5Sensitive to water changes
Sudden shifts in water chemistry or temperature can stress this species. Take time to acclimate new arrivals gradually, and keep up with regular partial water changes afterward.
6Lifespan of 3-5 years
With a stable environment, Harlequin Rasboras typically live around three to five years. Consistent water conditions and regular feeding go a long way toward a long, healthy life.
7Breeding takes some care
They scatter eggs among fine-leaved plants, but breeding them successfully at home takes fairly specific conditions. If you're not aiming to breed them, a standard, well-maintained setup is all you need.

Frequently asked questions about Harlequin Rasbora

Q.Is this fish suitable for beginners?: A.Yes — Harlequin Rasboras are generally considered beginner-friendly and adapt well to typical aquarium conditions. That said, they're sensitive to sudden water changes, so acclimate them carefully when introducing them to a new tank.
Q.How many should I keep together?: A.Since they're a schooling species, it's best to keep at least six to ten together. Smaller groups tend to be skittish and spend more time hiding.
Q.Can it be kept with other fish?: A.Yes, its peaceful temperament makes it a good tankmate for other calm, similarly sized fish. Avoid pairing it with aggressive species or fish that are much larger.
Q.What should I feed it?: A.Harlequin Rasboras readily eat artificial flake or pellet food as well as frozen food, and aren't fussy eaters. Since their mouths are small, small-sized food fed in modest portions works best.
Q.How big does it grow and how long does it live?: A.Harlequin Rasboras stay small, reaching about 3 to 4 cm as adults, and typically live around three to five years. Their compact size makes them easy to fit into a modestly sized tank.

Useful tools for Harlequin Rasbora care

💧Aquarium Volume CalculatorCalculate water volume, weight, and heater wattage from tank dimensions 🧪Water Quality CheckerFind compatible fish, shrimp, plants & corals based on pH, temperature & hardness 🍽️Feeding GuideCheck feeding frequency, portion sizes & supplements by species and growth stage 🤝Compatibility CheckerCheck compatibility between two species on a 5-level scale 📊Fish Compatibility MatrixCheck fish compatibility at a glance with our matrix chart 🔄Nitrogen Cycle GuideAuto-calculate bacteria colonization timeline for new tank cycling 🗓️Seasonal Care CalendarMonthly care events and seasonal management tips at a glance 🚿Water Change CalculatorAuto-calculate optimal water change frequency and volume by tank size and fish count 🐠Stocking CalculatorCalculate max fish capacity for your tank size with overstocking alerts ⚡Electricity Cost SimulatorCalculate monthly and annual electricity costs for care equipment with presets 🧬Breeding PlannerSelect parent varieties to view breeding schedules and offspring patterns 🏞️Tank Layout PlannerGet substrate, plant & hardscape suggestions based on tank size and style 🧮Care Cost SimulatorEstimate initial, monthly & annual costs by category, care level and quantity ⚖️Species Comparison ToolCompare two species side by side: care difficulty, size, lifespan & temperature 🎯Pet Match DiagnosticAnswer 7 questions to find your top 3 perfect pets 📋Lifetime Cost SimulatorEstimate lifespan and lifetime costs by species for dogs, cats, reptiles and more 🚚Transport Safety CheckerCheck transport safety score and precautions by category, season, method and distance 💊Medication Dosage CalculatorCalculate proper medication dosage by body weight and medicine type for fish, reptiles, and small animals ⏱️Quarantine & Acclimation TimerManage quarantine periods and acclimation steps with countdown timers. Includes recommended durations by species

Learn more about Harlequin Rasbora in the encyclopedia

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Care difficulty, lifespan, size and diet — all basics covered.

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