The Bronze Featherback Notopterus notopterus gets its name from the small dorsal fin on its back. This fin stands upright and sways back and forth just like a feather in the wind.
The adult Featherback will be a plain brown while juveniles have dark bars along the entire length of the body. The recent availability of a farm produced albino version (pictured above) is an exciting development. Common names it is known by include Grey featherback, Asian Knifefish, Featherfin Knifefish, and Asiatic Knifefish.
Although not particularly colorful, the Featherfin Knifefish is very interesting to watch and is well worth keeping as a pet. It has a flat elongated body with an arched back. There is a continuous fin along the underside formed by a joining of the caudal and anal fin. This fin undulates, allowing it to move either forwards or back wards, making it a very graceful swimmer. These fish are often confused with the African Knife FishXenomystus nigri. But the African Knife fish can readily be distinguished because it lacks a dorsal fin and is smaller.
The Asian Knifefish species is a member of the Notopteridae family which contains some of the more outgoing species. Some of the members of the Notopteridae family, such as the Clown Knifefish, can grow to huge proportions. The Bronze Featherback can grow to be relatively large in the wild too, reaching up to 24 inches (60 cm). But tank raised fish over 12 inches are rare so you shouldn’t have to worry about eventually dealing with a 2 foot long fish. However, there can be exceptions so you will want to keep their potential size in mind.
The Bronze Featherback need a minimum sized tank of around 40 gallons when young, especially if keeping other fish with them. They will need a larger aquarium of 150 gallons or more as an adult. This knife fish is a rather belligerent species. It will generally get along with peaceful fish bigger than itself, but is very territorial and quarrelsome with others of its own kind. It should be kept singly unless the tank is very large.
These Grey featherback Knifefish are suggested for an aquarist with some fish keeping experience. They can be hard to get adjusted to a new tank. Being nocturnal they need places to retreat during the day as well as open areas for swimming. Once acclimated, they are very hardy fish.
The Bronze Featherback Notopterus notopterus was described by Pallas in 1769. They originate in Asia from southern India, Pakistan, Nepal, Bangladesh, Laos, Cambodia, Myanmar and in most coastal river basins of Thailand, Viet Nam, Malaysia, Indonesia Malaysia, Sumatra and Java. Other common names it is know by are Grey featherback, Asian Knifefish, Featherfin Knifefish, and Asiatic Knifefish.
The species is listed on the IUCN Red List as Least Concern (LC) as it has an extremely wide distribution. Its status is not really definitive because Its taxonomy is in an undetermined state at present. It is suggested to most likely be a species complex.
They normally inhabit slow moving streams and canals. They are also found in rivers and ponds. As with many knifefish, during the rainy season they migrate to the flooded forests to breed. There is also recorded evidence that these Knife fish will live in brackish water for short periods of time. They will most likely not survive in a tank that is brackish. In nature this fish feeds on insects, fish, crustaceans and some young roots of aquatic plants.
The Featherfin Knifefish are highly sought after as food fish in their native lands. It is also believed that eating soup made from this fish has health enriching properties, and will cure many diseases. It's a common remedy given to people with measles.
Scientific Name: Notopterus notopterus
Social Grouping: Solitary
IUCN Red List: LC - Least Concern
The Bronze Featherback can reach up to 24 inches (60 cm) in the wild, but most tank raise specimens won't grow much larger than 12 inches (30 cm). The body is flat and elongated with an arched back. It has a continuous fin along the underside formed by a joining of the caudal and anal fin. It is a graceful swimmer as this fin allows it to move both forwards and backwards. It also has a very small dorsal fin.
Adults are a plain brown while juveniles will have dark bars along the entire length of the body. The Bronze Featherback pictured above is an albino colorform. This fish looks much like the African Knife fish but can be distinguished by their larger size and presence of a dorsal fin.
Size of fish - inches: 23.6 inches (59.99 cm) - These fish can get up to Up to 24 inches (60 cm) in the wild, but most tank raise specimens won't grow much larger than 12 inches (30 cm).
Lifespan: 15 years
Fish Keeping Difficulty
This Asian Knifefish is suggested for an aquarist with some fish keeping experience. They can be hard to get adjusted to a new tank. They are very hardy fish once they reach a certain size, but can be sensitive to water conditions and some medications when they are small. Many young knifefish die soon after purchase normally due to shock or unsuitable tank and water conditions. Being nocturnal they need places to retreat during the day as well as open areas for swimming. Once acclimated, they are very hardy fish.
Aquarium Hardiness: Moderately Difficult
Aquarist Experience Level: Intermediate
Foods and Feeding
The Bronze Featherback is considered an omnivore because they do eat some vegetation, but primarily they eat protein foods. In the wild they begin to eat when the sun sets and continue throughout the night, feeding on insects, fish, crustaceans and some young roots of aquatic plants. In the aquarium they can be fed small fish, worms or small shrimp. Some can be trained to eat freeze dried foods or high quality flake food.
Diet Type: Omnivore
Flake Food: Occasionally
Tablet Pellet: Occasionally
Live foods (fishes, shrimps, worms): Some of Diet
Vegetable Food: Some of Diet - It eats some young roots of aquatic plants in the wild.
Meaty Food: All of Diet
Feeding Frequency: Daily
This fish is scaleless and very sensitive to water condition changes. A high quality filter is a must! Weekly water changes of about 30-50% are needed. Water condition tests should also be done weekly to make sure levels are not spiking.
Water Changes: Weekly - Do a 30 - 50% water change weekly.
The Bronze Featherback will spend most of its time near the bottom of the tank. An aquarium of around 40 gallons will work when they are young, especially if keeping other fish with them. They will need a larger aquarium of 150 gallons or more as an adult. Use a high quality filter with low water flow. A UV sterilizer is a smart thing to incorporate into your tank as these fish are very sensitive to medications. The UV sterilizer will kill many diseases.
It requires an aquarium with many hiding places and sheltered areas as well as unobstructed swimming room. Plants are best especially along the back and sides to leave some open area for swimming. Plants with long twisted roots offer hiding places for your Knife Fish. Areas of dense planting, large chunks of bogwood, rock piles and lengths of plastic piping are all possible alternatives. Soft sand is the best choice for the substrate.
It is a largely nocturnal species and prefers dim lighting. Floating plants can help to break up and subdue any light. Provide them with a dimly lit tank and you should have a happy Featherfin. In the right setting the fish will often be seen during daylight hours. Using Moonlight LED lights will give you the best viewing of this amazing fish at night.
Minimum Tank Size: 40 gal (151 L) - A 40 gallon tank will work when they are small, especially if keeping other fish with them, but they will need a larger aquarium of 150 gallons as adults.
Suitable for Nano Tank: No
Substrate Type: Sand
Lighting Needs: Low - subdued lighting
Temperature: 75.0 to 82.0° F (23.9 to 27.8° C)
Range ph: 6.0-6.5
Hardness Range: 2 - 12 dGH
Brackish: No - These Knife fish will live in brackish water for short periods of time in the wild, but they will most likely not survive in a tank that is brackish.
Water Movement: Weak
Water Region: Bottom - The Featherfin Knifefish will spend most of its time near the bottom of the tank.
Although they are usually relatively peaceful, individual specimens can become aggressive. They probably won't kill anything that's too large to be able to fit into their mouths, but they may damage the fins on fish that are slow or that have long fins. They are very intolerant of their own kind and require a huge tank if you want to try to house 2 in the same tank.
Same species - conspecifics: Sometimes - This knifefish is very territorial and quarrelsome with others of its own kind. It should be kept singly unless the tank is very large.
Peaceful fish (): Monitor - This fish is rather belligerent and it will be aggressive towards smaller fish and eating any small enough to be considered a meal.
Semi-Aggressive (): Threat
Aggressive (): Threat
Large Semi-Aggressive (): Threat
Large Aggressive, Predatory (): Threat
Slow Swimmers & Eaters (): Monitor - They are usually fine with larger tank mates that are big enough to not be considered food, but may damage the fins of slower fish.
Shrimps, Crabs, Snails: Threat - is aggressive - In the wild, this fish hunts at night for worms, crustaceans, insects and snails.
Sex: Sexual differences
Sexual differences are unknown.
Breeding / Reproduction
Breeding has been done in aquariums, but is more of a rarity. One of the earliest reports of breeding was accomplished by Van Pinxteren in 1974 (Datz 27, 364-369), as shared by authors Dr. Rüdiger Riehl and Hans A. Baensc in their book, Aquarium Atlas Vol. 1. They report that, "The fish spawn in the night, dropping eggs to the bottom and on rocks. They were guarded by the male who fanned fresh water over the eggs with his pectoral fins, chasing off all other fishes. The eggs required two weeks to develop and the newly hatched young were sensitive to handling."
Featherfin Knifefish are mass-produced fish in commercial fish farms in many of their native countries. They are commercially spawned in Thailand but the method being used is not known. In aquariums the eggs are normally laid on the substrate or decor and guarded by the male till they hatch which is usually 2 weeks. Once free swimming these fry will feed on brine shrimp nauplii and microworms. These fish are intolerant of their own kind, so a huge tank would be need and a large influx of cold water added to the tank to trigger spawning.
Ease of Breeding: Difficult
The Bronze Featherback does not have scales which make it more prone to disease. Knifefish are normally the first fish in a tank to show signs of ick and will twitch and rub around the tank. They respond well to most medication and normally heal quickly. NEVER use copper in a Featherfin Knife Fish tank. Overall these fish are hardy and disease is not usually a problem in a well maintained aquarium. That being said there is no guarantee that you won't have to deal with health problems or disease.
Anything you add to your tank can bring disease to your tank. Not only other fish but plants, substrate, and decorations can harbor bacteria. Take great care and make sure to properly clean or quarantine anything that you add to an established tank so not to upset the balance. Because these fish eat live food, disease can be passed to them from their foods. Make sure to quarantine live food before feeding.
When keeping more sensitive types of fish, it is common for all fishes to be infected even before the first warning signs can be noticed. The best way to proactively prevent disease is to give your fish the proper environment and give them a well balanced diet. The closer to their natural habitat the less stress the fish will have, making them healthier and happy. A stressed fish is more likely to acquire disease.
As with most fish the Asian Knifefish are prone to skin flukes, parasitic infestations (protozoa, worms, etc.), ichthyobodo infection, parasitic infestations (protozoa, worms, etc.), bacterial infections (general), and bacterial disease. It is recommended to read up on the common tank diseases. Knowing the signs and catching and treating them early makes a huge difference. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.
The wild color version of the Featherfin Knifefish is commonly available. The albino version is quite a bit rarer but since they are now being bred in captivity, they should become more commonly available in the near future.
Saphira - 2011-11-29 I once saw a type of aquarium fish in a pet store, which I have never seen again. They looked like beautiful black feathers and they were almost vertical whilst swimming. I've tried to look them up everywhere but no luck so far. If anyone can satisfy my curiosity, I would be grateful.
whiteaura - 2006-11-10 I own several tanks. I have a 135 gallon and 170 gallon empty, as I'm just waiting for them to grow. I even have access to a 1200 gallon tank! I think waiting until they grow up would be more prudent before moving them, eh? Update: my albino asiatic has calmed down considerably. Apparently, it could not select a spot to call home. After it selected one, it loves to stay inside of the big cave in seclusion. My conclusion: its original extra aggression was due to no hiding place to call home (wandering around without a home made it aggressive). I STILL would not call it peaceful. Out of the five knife fishes, this is the only one that snaps with its mouth when someone enters its cave. *SPACE* advise: surely, cramped quarters is always a reason fish gets surly and uncomfortable.
hasham - 2011-03-10 These fish are territorial with other of same kind and quite aggressive to other fish as well. So not peaceful at all. It would like to dig in substrate much like Cichlids. Mine would take sinking pellets and feeder fish.
whiteaura - 2006-09-25 I just purchased an albino asiatic knifefish. It is 4" long. I put him in a 55 gallon tank that has a 3.5" blackghost knife; a 3.5" royal clown knife, a 3.5" silver clown knife, 4" african brown knife. The albino is absolutely not the shy type. It moves about the tank perpetually only occasionally stopping. It goes thru all the hiding places and chases out any knife fish it sees. All of the other knife fishes are a bit shy and like generally will stay in its hiding spot. The albino appears to be a little pushy and likes to assert itself. The only knifefish that can handle it is the african brown. The african brown has the most agility of movement when being chased by the albino. The albino tends to get a little aggravated when the african brown can easily dodge and put itself behind the albino. I'm not sure what to do with the albino. It is a bit more aggressive than the others and its perpetual motion reminds me of a giant danio. I'm a little disappointed that many internet sites claim that they are peaceful. My albino is very pushy with its tank mates.
Dan - 2011-01-08 This may sound crazy but a lot of fish actually do have personalities. However rare they may be - exceptions do exist. It can make fish either really entertaining , peaceful, or stressful to have and observe. I'm only speaking from my years of research and experience in fish in both marine and freshwater aquariums. Sometimes we take gambles - and sometimes things turn out alright ... other times .. not so much. This also applies to fish. (ex. Angelfish generally will eat tetras small enough to fit in their mouths [the chances are higher as the angels grow bigger], but I have seen both of them get along peacefully. That being pretty average sized angels. But I haven't seen this or heard of it very often at all - its a gamble)