Clown Knifefish

Chitala ornata

Oddballs

A massive, nocturnal predator native to Southeast Asia, widely known for the distinct row of ocellated spots above its anal fin. While sold as small silvery cute juveniles, they grow incredibly fast into nearly 1-meter giants that require immense aquariums. They are obligate carnivores and will eat any fish small enough to fit in their large mouths. They are shy during the day and require large hiding tubes or caves.

At a Glance

Adult Size90 cm
Body ShapeCompressed
Growth RateFast
TemperamentAggressive
Water TypeFreshwater Only
Flow PreferenceModerate
Waste OutputExtreme
StockingSolo only

Tank Requirements

Minimum Volume750 L
Minimum Length180 cm
FlowModerate
Water TypeFreshwater Only
Must-Haves in the Tank
Smooth Gravel (Sensitive Barbels)Driftwood (Digestion/Hiding)Plants - Densely covered

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Water Parameters

Temperature2428°C
pH67.5
Hardness515 dGH

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Keep water parameters stable with the right testing and heating gear.

Temperament & Compatibility

Aggression LevelAggressive
7/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least1 (solo is fine)
Max per Tank1
Can Live Alone?Yes
Behavior Traits
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)Aggressive to same species/look-alikesShy / Slow Moving (Easily Stressed)

Available Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Standard (Adult)

The fully grown adult form. Requires a tank with a footprint wide enough for it to turn around (at least 75cm width recommended). Highly territorial towards other Knifefish.

Differs in 1 trait from base species

Also known as: Adult, Monster Fish

Behavior Traits
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)Aggressive to same species/look-alikes

Juvenile (Grow-out)

Commonly sold size (10-15cm). Deceptively peaceful and shy. WARNING: Grows extremely fast. Will eat neon tetras and guppies immediately. Requires an upgrade plan to a 200G+ tank within 12-18 months.

Differs in 5 traits from base species

Also known as: Baby, Small

Adult Size15 cm
Min Volume200 L
Min Length120 cm
Growth RateFast
Behavior Traits
Piscivore (Eats small/nano fish)Fry PredatorHyperactive / Fast Swimmer

Albino / Golden

A color morph lacking the dark grey pigmentation. Care requirements are identical to the standard form.

Differs in 1 trait from base species

Also known as: Platinum, Gold

Behavior Traits
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)

Clown Knifefish Care Guide Summary

The Clown Knifefish, scientifically known as Chitala ornata, belongs to the Oddballs family group. Adults reach a maximum size of approximately 90 cm and have a compressed body shape with a fast growth rate. Classified as aggressive, this species primarily occupies the mid-level and bottom zones of the aquarium and produces a extreme level of biological waste.

To thrive, the Clown Knifefish requires a freshwater only aquarium with a minimum volume of 750 litres and a tank length of at least 180 cm. Water temperature should be maintained between 24°C and 28°C, with a pH range of 67.5 and a general hardness of 515 dGH. A moderate water flow is preferred. An aquarium test kit can help you monitor these values.

Due to its specialist needs, the Clown Knifefish is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 3 varieties: Standard (Adult), Juvenile (Grow-out), and Albino / Golden. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.

Clown Knifefish Habitat Setup

When setting up an aquarium for the Clown Knifefish, a moderate water flow best suits their natural preferences. Because this species occupies the mid-level and bottom zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include smooth gravel or rounded substrate to protect their sensitive barbels, driftwood, which can serve as both a hiding place and a dietary supplement, and dense planting to provide cover, break sightlines, and reduce stress. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper. Browse smooth aquarium gravel options to find the best fit.

Clown Knifefish Compatibility Notes

Classified as aggressive, the Clown Knifefish is best housed alone, as they do not tolerate others of their kind in confined spaces. When choosing tankmates, any fish small enough to fit in its mouth will likely be eaten, conspecific aggression can be intense, especially in smaller tanks, and boisterous or fast-moving tankmates may cause this species undue stress. Selecting tankmates that favour different water layers from the mid-level and bottom zones can help reduce competition and territorial overlap.

Clown Knifefish Feeding & Diet Considerations

The Clown Knifefish is a predatory species that will readily consume small fish, so nano or bite-sized tankmates should be avoided and is primarily active at dusk and dawn, so offering food shortly after lights-off ensures it receives adequate nutrition. Find quality Clown Knifefish fish food for this species.

Frequently Asked Questions About Clown Knifefish

How big does Clown Knifefish get?

Clown Knifefish (Chitala ornata) typically reaches a maximum adult size of approximately 90 cm. They have a compressed body shape and a fast growth rate.

What tank size does Clown Knifefish need?

A minimum aquarium volume of 750 litres and a tank length of at least 180 cm are recommended for Clown Knifefish. This ensures enough swimming space and helps maintain stable water conditions.

What water parameters does Clown Knifefish need?

Clown Knifefish thrives in freshwater only conditions with a temperature range of 24–28°C, a pH between 6 and 7.5, and a general hardness of 5–15 dGH. A moderate water flow is preferred.

Is Clown Knifefish peaceful or aggressive?

Clown Knifefish is classified as aggressive with an aggression score of 7 out of 10. Careful tankmate selection is essential to avoid conflict.

Can Clown Knifefish live with others of its kind?

No. Only one Clown Knifefish should be kept per tank. Keeping multiples in the same aquarium typically results in aggression and stress.

Does Clown Knifefish have any special tank requirements?

Yes. Clown Knifefish benefits from smooth gravel (sensitive barbels), driftwood (digestion/hiding), and plants - densely covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.

Does Clown Knifefish need a lid on the tank?

Yes. Clown Knifefish is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.


Similar Species

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Indonesian Datnoid (Tiger Fish)

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A massive, deep-bodied ambush predator highly prized by monster fish keepers for its striking black and gold 'tiger' stripes. Native to the freshwater rivers of Southeast Asia, they possess huge mouths and will consume any fish small enough to fit. They are notoriously shy when young but grow into bold, impressive centerpieces. Due to intense conspecific aggression, they should be kept entirely solitary or in groups of 4 or more to disperse bullying.

Red-Tail Catfish

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A massive, fast-growing predatory catfish from the Amazon basin. Famous for its voracious appetite, bulldozer-like behavior, and distinct red caudal fin. Due to its enormous adult size (often exceeding 4 feet), it is strictly a 'monster fish' that requires a heated indoor pond or a colossal custom aquarium. It is highly predatory and will swallow absolutely any tank mate that can fit into its cavernous mouth.