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.
Clown Knifefish At a Glance
Clown Knifefish Tank Requirements
Will Clown Knifefish fit in your tank?
Care guides tell you what Clown Knifefish needs, the next question is whether your tank can safely provide it. Test Clown Knifefish against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
We may earn from qualifying purchases
Clown Knifefish Water Parameters
Water care products
We may earn from qualifying purchases
Clown Knifefish Temperament & Compatibility
Clown Knifefish 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
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
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
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 6–7.5 and a general hardness of 5–15 dGH. A moderate water flow is preferred.
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.
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.
Feeding products
We may earn from qualifying purchases
.webp?2026-04-25T14%3A35%3A38.022Z)
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.
Plants That Suit Clown Knifefish
These plants pair well with Clown Knifefish based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Afzel's Anubias
Anubias afzelii
Amazon Sword
Echinodorus amazonicus
Anacharis
Egeria densa
Anubias Barteri
Anubias barteri
Baby Tears
Lindernia rotundifolia
Balansae
Cryptocoryne crispatula
Fish Similar to Clown Knifefish
African Knifefish
Xenomystus nigri
A fascinating nocturnal predator named for its blade-like shape. Lacking a dorsal fin, it moves by rippling its long anal fin, allowing it to easily swim backward and forward. While peaceful with larger tank mates, it is an opportunistic piscivore that will swallow any fish or invertebrate small enough to fit in its mouth. It requires dim lighting and plenty of caves (PVC or driftwood) to feel secure during the day.
Black Ghost Knifefish
Apteronotus albifrons
A fascinating nocturnal predator native to the Amazon basin. It lacks a dorsal fin and moves via a continuous undulating ventral fin, allowing it to swim backwards as easily as forwards. It generates a weak electrical field to navigate and hunt in the dark. Scaleless and highly sensitive to medications, it requires smooth hiding places (like PVC pipes or smooth driftwood). Will consume any fish small enough to fit in its surprisingly large mouth.
Chao Phraya Giant Catfish (Paroon Shark)
Pangasius sanitwongsei
An apex predator native to the Mekong and Chao Phraya basins. This true 'monster fish' is completely unsuitable for home aquariums. They grow to massive proportions, are highly active, and easily startled—often severely injuring themselves by crashing into tank walls. They possess a massive appetite and are highly piscivorous, consuming any tank mate that fits in their mouth.
Bullseye Catfish
Horabagrus brachysoma
A large, nocturnal predatory catfish native to the backwaters of Kerala, India. It is easily identified by the large, golden-ringed black 'bullseye' spot behind its gills. While completely peaceful toward tank mates too large to be swallowed, it is a highly capable piscivore that will consume any small fish overnight.
Frogmouth Catfish
Chaca chaca
An incredibly bizarre ambush predator native to South Asia. With a massive, flat head and cryptic coloration, they perfectly mimic a dead leaf or piece of wood. They are entirely sedentary, moving only to gulp down prey that wanders too close to their cavernous mouths. Because they can easily consume fish up to half their own length, tank mates must be chosen with extreme caution.
Pungas Catfish
Pangasius pangasius
A colossal riverine catfish native to the Indian subcontinent. While highly important for aquaculture, they are disastrous for home aquariums. They grow rapidly to enormous sizes (up to 150-300cm), are easily spooked (often resulting in them ramming the tank glass at high speeds), and will swallow any tank mate that fits in their massive mouths.