Clown knifefish (Chitala ornata)

Clown knife fish or clown featherback (Chitala ornata) is a large fish with an unusual body shape. The fish is kept in home aquaria due to its uncommon appearance. However, keeping this fish has some peculiarities about which you will find out from our article.

Habitat in the wild

In the wild inhabits large rivers located on the South and South-East of Asia, in Thailand, India and Burma. The fish dwells everywhere, it lives in main river bed of Mekong and Chao Phraya.

The fish was introduced into other countries including the USA (Florida). This fish inhabits lakes, bogs, backwaters of large rivers. Young species gather into groups and hide among the aquatic plants and snags.

The adult species are loners, they hunt from a hide by staying downstream among thickly growing plants.

Clown featherback is a nocturnal predator, that lives under roots of riverside trees and snags in slow, muddy and warm rivers and backwaters. It lies in the dark and waits for its prey in the hide. If fish is hungry, it will prey on any organism that it can swallow.

Here we have to mention, that the fish is full of itself – it is capable of attacking fish that is just one forth smaller than clown knifefish. In its birthplace this fish is a commercial one and it is widely used as food.


In the wild length may reach 1 m (3.3 ft), however at tank conditions it grows smaller, usually about 50 cm (20 inches) long. Its lifespan is about 10 years.

The fish has humpbacked elongated body flattened from sides with small scales; it has silvery-gray color. There is also an albino kind of the fish; it has a row of round dark spots with white edging along its body, their number varies from 6 to 15.

The dorsal is so small that it rather resembles a small feather, than a fin. Things are quite the opposite as for the anal fin – it is rather long: it stretches starting from pectoral fins and smoothly transfers into the tail fin. The fin moves all the time, due to this the fish can swim.

Anal fin of the young species has bright pattern on it, that consists of lots intersecting lines. The brighter is the pattern on the anal fin of rising fish species, the more pronounced and large spots on their body they will have when they become reproductive. Pectoral fins allow the fish to perform various moves when swimming.

Large mouth has many small teeth. Distinctive feature of the fish is that it can swim both forward and backward.

The fish respiratory organs are constructed so, that it can breathe with oxygen saturated in water and with atmospheric air. You can often see how you pet rises to the water surface to gasp an air bubble.

Difficulties in keeping

This fish is challenging in terms of keeping. For this reason it can’t be recommended for beginners – you will need a tank with balanced environment and at least some experience.

Keeping in a tank

Scientific NameChitala ornata
Common NameClown knife fish, clown featherback, clown knife, clown night fish, clownknife fish
Tank size500 liters (110 gallons) and more
Temperature75 to 85 °F (24 to 29 °C)
Sizeup to 1 m (3.3 ft)
Lifespanup to 10 years

Large size of the fish implies having specialized and very large tank. As for the recommended tank volume – this is a controversial issue. On one hand, the fish can grow up to 1 meter long, on the other hand – it seldom becomes that large in a tank.

Anyway, the tank volume has to be at least 500 liters (110 gallons). However, ideally it has to be twice as large.

Powerful external filter is a must as well as moderately strong water flow in the tank. It is better to use external filter with UF-sterilizer, since the fish is very sensitive to medicines and in this case prevention is the best idea. Besides this, clown featherback produces a lot of waste and feeds on protein food, its leftovers spoil the tank water very quickly.

As for the tank plants, you should put them along side and back walls of the tank to leave the fish a place to swim as well as shelters to hide.

The thing is that all species are active at night. During the day they try to hide under snags or among the plants and come out when it is getting dark.

Caves, snags, thickly planted tank plants – all these will do as shelters for the fish. It is timid and if there is no place to hide in a tank during the day, they will be constantly stressed and try to hide in some dark places in a tank. As for the open areas in the tank, it’s better to shadow them by means of floating plants.

Clown knifefish spends most of its time in middle or bottom water layers of the tank, but sometimes it can rise to water surface to gasp some air or get some food.

Optimal tank water temperature is from 75 to 85 °F (24 to 29 °C), hardness – up to 10 °, pH – 6.0–6.5. It is important to have aeration and filtration in the tank as well as weekly renew of 30% of tank water.

To make sure that the fish will live long and happy life, create it a tank with clean water, moderate water flow and lots of shelters.


This is a predator. It feeds on small fishes, crustaceans and other spineless species. In a tank the fish eats live and frozen food. For example, you can feed the young fish with bloodworm, small earthworms, sliced prawns etc.

As for the adult species, you can feed them with some fish pieces, whole prawns, large earthworms. It is desirable to feed the fish regularly with live food – fishes, prawns.

Clown knifefish are quite picky and may refuse eating the food you give them, you may also see how the adult species refuse taking the food they ate eagerly some time earlier.

Compatibility and tank mates

As we’ve mentioned above clown knifefish is a predator that demonstrates aggression not only towards other species, but towards its kind as well.

It is better to keep such pets in singles or with tank fishes of similar size. The fish is peaceful towards large sized fish species, those the fish is sure it won’t be able to swallow. Therefore, possible tank mates can be the following: pleco, bala shark, arowana, giant gourami, iridescent shark, sailfin pleco and so on.

It is not recommended to keep the fish with aggressive cichlids (flowerhorn, red terror), since despite the fish is aggressive, it is timid at the same time.

We strongly recommend not to keep two males of this fish kind in one tank, since when they fight, they harm each other quite seriously.

Gender differences: male vs female

Males have large, but slim body if compared with that of the females. The latter have more rounded abdomen during the spawning period.


Spawning in captivity is possible, but it happens very seldom because for successful breeding the fish requires a very large tank.

By the age of three years old the fish becomes reproductive. Put the fish into a separate tank of large volume to breed. There should be shelters and flat stones on its bottom as well as some floating plants on the water surface.

One female lays about 2-10 thousand of large yellowish eggs on floating plants.

As for the proper tank water parameters, they are the following: water temperature 26–28 °C, hardness – до 5 °, pH – 6,0–6,5. During the egg stage that lasts almost for a week the male takes care of the future offspring: he guards and cleans the eggs from settling organic waste.

Except this, the male provides flaw of water to the eggs by waving its tail fin. Once the juveniles hatch, you have to put them into a nursery tank right away.

Brine shrimp nauplii can be used as start food for juveniles.

About author: Sergey Schulz

Sergey is a founder and author of He’s been fond of aquarium husbandry since his early childhood. His favorite aquariums are biotopes (Amazon River), with Echinodorus and freshwater angelfish. However, through the years he’s had experience of keeping almost all types of freshwater fish and shrimps.