Chitala ornata
Encyclopedia
The clown knifefish, clown featherback fish or spotted knifefish, Chitala ornata, is a nocturnal tropical fish with a long knife-like body.
y gray with a long knife like body (laterally compressed) and a long anal fin that gives these fish their common name. Mature fish normally have 5-10 (or even more) black spots ringed with white that usually increase in number and size as the fish grows. Juvenile fish have stripe
d bands instead of spots. Their long anal
fins
are used to allow the fish to make graceful forward and backward movements.
The clown knifefish grows to a fairly large size, up to 100 cm and 5 kg in the wild. It has 2 nasal
tentacles above their large toothed mouth. In the center of the body there is a flaglike dorsal fin
and has no ventral fins. Most clown knifefish are afflicted with cloudy eye color when they age, it is perfectly normal.
hours. They normally hunt live prey and will try any fish that fits into their mouths. Young clown knifefish usually school
near water logs and plants for security, whereas more mature specimens usually become territorial and eventually become loners. These fish can also breath air to survive in stagnant waters and little oxygen
. The clown knifefish prefers water around neutral pH
and temperature ranging from 75 to 85 F.
, specifically Thailand
, Borneo
, Malaysia, India
, and Sumatra
.
These fish usually are found in lake
s, swamp
s, and river backwaters. They prefer still waters and can survive with low oxygen.
These fish enjoy periods of retreat, so aquariums which have cave
s, plants, or other hiding places are preferred. They are jumpers, so the lid should be kept tightly closed (with weights - larger specimens may knock the lid out). Dim lighting may help lessen jumping issues. For the first few days, clown knifefish are shy and prone to hiding. As they grow larger they tend to be quite the opposite.
These fish have their own personalities, attaching themselves to their handler
s to the point of being "hand-held" when moving or doing some maintenance.
, ghost shrimp and blackworms. With time they can be adapted to foods such as beefheart and will sometimes learn to accept commercial food pellets. They are mostly nocturnal, thus prefer feeding when the lights are off.
Appearance
The clown knifefish is very distinct, with normally silverSilver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
y gray with a long knife like body (laterally compressed) and a long anal fin that gives these fish their common name. Mature fish normally have 5-10 (or even more) black spots ringed with white that usually increase in number and size as the fish grows. Juvenile fish have stripe
Stripe
Stripe or Stripes may refer to:* Stripes * Stripes * S.T.R.I.P.E., a fictional superhero* Striper, a fish* Stripes Convenience Stores* Data striping, a data storage technique...
d bands instead of spots. Their long anal
Anus
The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...
fins
FINS
FINS is a network protocol used by Omron PLCs, over different physical networks like Ethernet, Controller Link, DeviceNet and RS-232C....
are used to allow the fish to make graceful forward and backward movements.
The clown knifefish grows to a fairly large size, up to 100 cm and 5 kg in the wild. It has 2 nasal
Nose
Anatomically, a nose is a protuberance in vertebrates that houses the nostrils, or nares, which admit and expel air for respiration in conjunction with the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes through the pharynx, shared with the...
tentacles above their large toothed mouth. In the center of the body there is a flaglike dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
and has no ventral fins. Most clown knifefish are afflicted with cloudy eye color when they age, it is perfectly normal.
Behavior
They are nocturnal creatures and usually cruise during the twilightTwilight
Twilight is the time between dawn and sunrise or between sunset and dusk, during which sunlight scattering in the upper atmosphere illuminates the lower atmosphere, and the surface of the earth is neither completely lit nor completely dark. The sun itself is not directly visible because it is below...
hours. They normally hunt live prey and will try any fish that fits into their mouths. Young clown knifefish usually school
School
A school is an institution designed for the teaching of students under the direction of teachers. Most countries have systems of formal education, which is commonly compulsory. In these systems, students progress through a series of schools...
near water logs and plants for security, whereas more mature specimens usually become territorial and eventually become loners. These fish can also breath air to survive in stagnant waters and little oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
. The clown knifefish prefers water around neutral pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
and temperature ranging from 75 to 85 F.
Location
Most knifefish species come from Southeast AsiaSoutheast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
, specifically Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
, Malaysia, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, and Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
.
These fish usually are found in lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
s, swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
s, and river backwaters. They prefer still waters and can survive with low oxygen.
In the aquarium
Clown knifefish are sold as exotic fishes in pet stores, but they grow much too large for the average home aquarium. It is necessary to keep in mind that these fish will grow fast and very large even in captivity (about 50 cm), so should be kept in aquariums of at least 500 liters in order to reach their full growth potential. It is not advised to have tankmates small enough to be considered food.These fish enjoy periods of retreat, so aquariums which have cave
Cave
A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...
s, plants, or other hiding places are preferred. They are jumpers, so the lid should be kept tightly closed (with weights - larger specimens may knock the lid out). Dim lighting may help lessen jumping issues. For the first few days, clown knifefish are shy and prone to hiding. As they grow larger they tend to be quite the opposite.
These fish have their own personalities, attaching themselves to their handler
Handler
- People :* Animal handler, person who conducts animal training or is a wrangler * Handler, a coach, sports agent of a sports player, or entertainer promoter* Agent handler, person who manages a spy...
s to the point of being "hand-held" when moving or doing some maintenance.
Feeding
Clown knifefish are hearty eaters, one of the reasons people like them as pets. They are predatory fish and will take live foods such as feeder fishFeeder fish
Feeder fish is the generic name for certain types of inexpensive fish commonly fed as live prey to captive animals such as sharks, turtles and some other fish such as oscars.-Advantages of using feeder fish:...
, ghost shrimp and blackworms. With time they can be adapted to foods such as beefheart and will sometimes learn to accept commercial food pellets. They are mostly nocturnal, thus prefer feeding when the lights are off.