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Main Index > Detailed Fish Profiles > Miscellaneous species > Clown knife
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photo courtesy of Aqualand pets plus

Chitala chitala



    Another monster of the hobby, the Clown knife should not be purchased by the casual hobbyist. Reaching huge sizes few people can properly house them and fewer can help them thrive.

Quick stats:

    Listed tank sizes are the minimum
    Size: Up to 40" (100cm)
    Tank: 48 inches (when small)
    Strata: Bottom, middle
    PH: 5.5 to 7.0
    Hardness: Soft to medium. dH range: 2-10
    Temperature: 75°F to 82°F (24-28°C)

    Order: Osteoglossiformes
    Suborder: Notopteroidei
    Family: Notopteridae
    Genera: Notopterus

Common name:

    Clown knife fish, Featherback

Image gallery:
    Additional species photographs


    Badmans' Forum
    Asia, found in India, Thailand, Borneo, Malaysia and Sumatra.
General body form.
    Long knifelike bodies. There are two Nasel tentacles above the large, toothed mouth. Six or seven fin rays support the little flag-like Dorsal fin, which is usually located at the center of the body. The center ridge along the belly is distinctly serrated. The fish has no Ventral fins. They can reach a length of two feet
    Generally silver, with a Brown tinge. The most striking feature are the circular markings along the middle area of the fish. These circles increase in size and number as the fish grows.
    These fish range in various types of water in their home territories. When they are young they live, communally in large numbers among submerged roots and water plants. They prefer the more peaceful parts of rivers, and can be found in large areas of standing water. They are nocturnal in habit and do not come out until twilight. Adults are territorial and sedentary in habit.

    The aquarium for the knife-fish should be large with a small grained substrate. It should be fairly densely planted with many floating plants. Driftwood is also recommended along with some sort of inert piping for the fish to hide in. The water should be soft, and kept at a temperature of between seventy-five and eighty-two degrees. The pH should be neutral to acid. They are predatory in nature and need to be feed live food ranging from guppies to goldfish. Quality frozen food can be eventually accepted. Although a large and predatory fish the Clown-knife is very timid and any tankmates must be of the same nature and large enough not to be eaten.

    In general only juvenile specimens are suitable for the home aquarium.

    Found in calm, large rivers and backwaters that are overgrown.
    Because only young fish are kept and never reach maturity, as far as I can find out they have not been breed in captivity.

Your comments:


Please remember that the following comments are personal experiences and may or may not apply to your setup. Use them as guide to help better understand your fish, like us all individuals will behave differently under different circumstances.


From: Jesse
I work at a fairly large privately owned LFS where I work as an aquarist and I bought a BGK at 3-4" about a month ago and ever since he got in he made the fake bonsai tree his home and the drift wood as his front yard which he occasionally uses as his chillspot outside the bonsai tree I've had him (now 5") with a royal clown knife 4", royal pleco 3", syno eupterus 3", tire track "eel" 7", endichair bichir 5",and an electric blue Jack Dempsey that I just introduced last because he's the expected most aggressive out of all of the and he's at a small 1.5-2" and they are all happily in their houses that currently accommodates their sizes. The BGK let's the tire track chill next to him but he has his times where the best I can describe looks like he "pouts" and with graze them with his body gently like a little nudge when the fish are around him and he wants to be alone especially when the lights are on and he wants to sleep. At night he likes to swim around the back where my take and live plants are and the heater. And occasionally (like right now) he swims out of his house backwards and swims around backwards which I find to be one of his best features is his movement with one lone anal fin. Then again I like the weird fish.
From: Weston
I just wanted to state I purchased 2 of these fish about 6 months ago at under 3 inches I also purchased at the same time 2 Oscar, 1 Jack Dempsey, 3 silver dollars, and a larger pictus and planed to add a silver arowana all of these fish were doing fine until I started seeing wounds on my both of my clown knifes I suspected possibly the Oscar or the Dempsey but after pulling these guys and placing them in a quarantine I found they were doing it to each other these fish can be very aggressive to one another I've since read keep solitary or in groups of 3, both of these fish do incredibly well in my Oscar tank but only one at a time I've rotated them to keep from stunting the growth of either fish being kept in the grow out as its a smaller tank, recently after moving some tanks around I tried keeping one of these with my giant gourami and it was a bad mix the gourami had some scrapes on his side and the clown knife had beaten tattered fins but I'm skeptical as to such fish started the fighting as both have been great in semi- full out aggressive community setups so far either way don't try this or do and let me know if it works for you! Hope for the best.
From: Delshawn Christian
I have 2 clown knives that I bought about 3 months ago. The love goldfish, earth worms and are beginning to eat shrimp chunks more and more. They in a tank with many tank mates and seem to get along with them. They are very private fish and spend most of their time hiding until you introduce dinner. I love these fish because they are so unique.
From: Ray
My wife and I happen to be shopping one day and came across a Petland Discounts in a small shopping center and decided to walk in on Fathers Day of June 15 of 08. As we are browsing the tanks there were some clown knifes in a tank about 2 inches. There was 4 of them, barely any spots, did not look like clown knifes at all. I asked the girl working there if they were eating, she tells me "Yeah, I feed them flake food everyday". Now I started to wonder, wait a minute these guys are picky eaters, how true can that be, so I asked her "Do you mind feeding them so I can see them eat?" She said "okay". Sure enough they went crazy over the flake food. I still found this unusual being that I have owned these fish at previous times in my life and had to find methods of feeding and foods like silversides, beefheart, frozen prawn, krill and other meaty items for them. Well I bought all four...

It is now Aug 28 of 08, over 2 months later and they have grown about 10 inches and swim around all day long and eat out of my hand and not afraid to come up to the surface to grab krill when I feed my 3 Arowanas they live with them in a 200G tank. They eat everything ; flake food, pellets, freeze dried stuff and all types of frozen foods and even market shrimp. They are growing very quickly and chances are they will reach a length of 24" within the next 4 months. I have owned knifes before, but not like these four, they get along just fine and not afraid of any movement in front of the tank and when you approach they all come to the front. They don't bother any of the other fish in the tank with them and what a great personality for these four and I am happy I walked into that store at that time. It was a great Fathers Day Gift to myself...
From: Topn01
I've been keeping fish for about 45 years now, and Clown Knife..has to be one of my all time favorites. I've always kept larger fish and I bought him about a year and a half ago when he was about 4" in length. He's 18"+ now. He eats at least three large nightcrawlers every day. He's also been known to eat some of the Cichlid pellets that I feed his tankmates. I usually feed when I come home for lunch, and he's always waiting in the corner of the tank that I feed from. He's housed in a 90 gallon tank with a school of large silver dollars and some assorted New World Cichlids. No compatibility problems at all. He pretty much ignores his tankmates. He's not really demonstrated nocturnal behavior in that he's pretty active round the clock. If you're looking to get one, I wouldn't unless you have or plan to obtain a tank in the 125+ gallon range. He's going into a 150 pretty soon. Spook has been pretty hardy, but at the same time he's the first to react to water quality issues, so keep the partial water changes up. Make sure there is somewhere that the fish can hide also. You can check out a video of Spook here.

From: Erick
I've had a Clown Knife for a little over 4 years, he is 28" and in a 240g tank he is almost about to out grow it but so far so good, I have not had luck keeping peaceful tank mates with him. A year ago I had a 15" Silver Arowana with him but he jumped out. I feed him 50 feeder goldfish a week along with some Crayfish and Prawns, try to stay away from live food as much as possible because once he is on it he will not stop. Overall Great fish, not for the poor great personality they also recognize there owner. Soon to upgrade him to a 525g tank.

From: Britt Canese
I have owned and loved a clown knife for 15 years..he is over 21 inches and I have him in a 110 gallon tank. I bought him at about 4 inches and had him in a 55 galloon until he over grew it. I feed him 30 to 40 goldfish/guppies every 3 to 4 weeks...water change a third of the tank once every 4 to 6 weeks only adding a good water conditioner. His tank has 2 300 filters on it . I change out the foam/carbon once every 3 to 6 months. I have a thermometer on it to keep him between 75 and 80 degrees...Herb is the coolest pet I have ever owned...although I have tried giving him some company over the years he has eaten them all. He is graceful,beautiful and if you can regulate,loving,feeding and cleaning a tank of this size he is soooo worth it. I have photos if I could post them somewhere I would. Enjoy your clowns!

From: Tim
I have had 2 clown knifes for the last 2 years. I got them when they were about 2-4 inches. I heard they don't get a long very well with each other as they get older but mine have been the best of buds. They're both roughly around 19" in a 125 gallon fish tank. I learned to raise fishes with these guys and they've been threw the extremes with me. They've have survive overtime I messed up. I'm very happy with my knifes since I learned so much from them. I'm getting a 300 gallon fish tank for them this week and I was trying to make it look perfect for them. They love to hide during the day but at night, anything smaller then 3 inches will be eaten. Its a big responsibility but in the end its worth having these beasts in the house.
From: John
I got my clown knife at 4" long. Its been two years and he is now 18 - 20" long. He is a bad ass. I feel bad though because he's in a 75gal and clearly needs more room. I've put ads around town at pet stores trying to sell or possibly even donate him to someone with a larger tank. He is happy though. He feeds eagerly and is a high level predator with size to his credit. He is housed with a 6" green terror, a 5" jack dempsey and a rhino pleco. Its a good tank and the fish are all perfectly happy and healthy but that clown knife is only getting bigger and will need to go soon. So just a warning to all of you that wander in to the local fish store, look at a small clown knife and say "ooh he's cool, I gotta have him". These fish are monsters. Be prepared.
From: Brandon
I recently bought a juvenile Clown knife on impulse. I really thought it was a beauty. Once I put it in the tank it began its stalker/hunting mode. I asked at the store and they said it would be fine in a community tank so after that night, nearly all of my fish we missing or missing fins *(most of my fish were glow-light and neon tetras). another thing is I had some feeder fish already, and tried to feed it to him after I realized his carnivorous nature. They tend to like smaller feeder guppies, minnows, goldfish or just frozen brine shrimp or blood worms. He is a feed at night fish and enjoys when the light is out but the nearby lamp is on (creates a dusk-like atmosphere). Watch them with your plecos too. Mine tried to attack mine, but since my two plecos had learned to hide a little better. Hope this is useful...







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