Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Chitala ornata

Clown knifefish

Clown knifefish, Chitala ornataClown knifefish, Chitala ornata
Photos by Andy Rapson


Chitala: Bangladesh local name; chitala: From rivers of Bengal & Behar.

General Notes:

Clown knifefish are often sold while still quite small but be warned they grow very big and will ultimately need a huge aquarium. They cannot be trusted with smaller fish and even fish which are to large to eat may be attacked. Clown knifefish need areas of open water for swimming and caves or other places in which to hide during the day. Clown knifefish are active during levels of low light at dusk and dawn and this is when food should be offered. Clown knifefish are able to utilise atmospheric oxygen which enables them to live in water which is low in oxygen. However this does not mean that they can live in polluted water and they have no more resistance to ammonia/nitrite poisoning than any other fish.


Wild clown knifefish prey on other fish, large crustaceans and surface insects. In captivity they will accept 'meaty' food such as whole fish, worms, beef heart and some individual will learn to accept pelleted food.


There are no external differences between the sexes.


Clown knifefish are difficult to breed because only large adults will breed and large adults are normally quite intolerant of each other. The male will guard the eggs until they hatch.

Wild status

The wild population of clown knifefish has not been evaluated.

Information at a glance

pH: 6.5 - 7.5
dGH: 5 - 15
Temperature: 24 - 28°C (75 - 82°F)
Diet: Carnivore
Size: 100cm (39in)
Min tank size: 1800 litres
Difficulty level: Intermediate
Aquarium type: Alone / Species
Swimming level: Lower

Distribution and habitat

distribution map for Clown knifefish, Chitala ornata

Origin: Asia: Mekong basin in Laos, Thailand, Cambodia and Viet Nam; Chao Phraya and Meklong basins.

Habitat: Inhabits flowing waters of large and medium-sized rivers. Within the Mekong mainstream, it occurs in pools. Found in the basin-wide mainstream of the lower Mekong. Moves into inundated forest during the high water period from June to October


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Osteoglossiformes
Family: Notopteridae
Genus: Chitala
Species: C. ornata

Common name:
Clown knifefish

Synonyms: Notopterus buchanani, Notopterus chitala, Notopterus ocellifer, Notopterus ornatus