Glass catfish (Kryptopterus bicirrhis)

Glass catfish (lat. Kryptopterus bicirrhis) — is a kind of freshwater ray-finned fishes of catfish family that inhabit in South-Eastern Asia. The first thing that catches the eye when you see this fish is how transparent it is – you can clearly see its visceral and spine.

So, it becomes quite clear why this fish is called a glass one. Glass catfish are rather sensitive to their tank water parameters change and it should be put only into a settled tank with low nitrates level. Besides, the fish is rather timid and sensitive one, so it should be kept only in a school and with some peaceful tank mates.

Habitat in the wild

Kryptopterus bicirrhis inhabits in Thailand and Indonesia rivers, prefers some streams and rivers with slow water flow, where the fish inhabits in a school and catches fish flowing by.


There are no pigments in the body, this catfish is transparent to the bone – you can see its skeleton and some inside. There is a spine line along the 6-10 cm long body, costal bones are also seen.

In the wild, in fish habitat such a body structure helps these harmless fish to hide from predators. Ghost catfish just disappears in the muddy water in the wild.

The number of melanophores (cells that contain pigment in them) is quite low, so the muscles are transparent and light colored. There’s one more pigment in the body except melanophore: it’s guanine that is responsible for metallic coloring.

This pigment develops inside the cells in form of crystal plates that act like a mirror, reflecting light and color of the environment and this way it makes the fish masked in water.

The fish has a couple of long barbels on its upper lip. Even though it may seem that the fish doesn’t have a dorsal fin, if you look closer, you can see a small fin right behind the head. However, glass catfish don’t have a flesh fin.

Difficulties in keeping

Care is rather difficult since the fish is quite a demanding one, that can be recommended only to experienced aquarists.

The fish hardly stands changes of tank water parameters, it is timid and prone to different diseases.

Care and keeping in a tank

Scientific NameKryptopterus bicirrhis
Common NameGlass catfish, ghost catfish, phantom glass catfish, clear catfish, thailand glass catfish, thai glass catfish, transparent catfish, phantom catfish
Tank size25 gallons (100L) and more
Temperature75–81 °F (24–27 °C)
Size15 cm (5.9 in)

In the tank it’s desirable to simulate the fish natural environment (which is streams and rivers with flowing water).

To achieve this use lots of live plants, however there should be some space for the fish to swim and some water flow running along the tank length.

Adding some fluctuants will make the fish fill safe and also they’ll create in the tank some shaded spots, which the fish likes some much in the wild.

This species is very sensitive to the water purity, so the water filtration must be very efficient and the tank water should be renewed regularly. Glass catfish don’t like bright light, therefore they are active in the shaded parts of the tank.

The fish feels more comfortable in a school of its kind. When being alone the fish may have bad appetite and hide all the time, also the fish alone doesn’t look as good as a school of glass catfish.

Glass catfish feel themselves much better and confident in a group of 4-6 fish, they swim freely in the middle water layer and in the middle of the tank.

To keep the fish healthy the tank water temperature shouldn’t be less than 26 C and there shouldn’t be any abrupt water temperature changes.

Also you should control the level of ammonia and nitrates in it, since this catfish is rather sensitive to these parameters. Here are some points that should be kept in mind when putting your ghost glass cat into a tank for the first time.

After being put into their new dwelling the freshwater glass fish may lay on the bottom of a tank. Don’t panic! They are just a bit stressed. As soon as they get acquainted with their new home, they’ll get up from the tank bottom and start swimming. You may sufficiently lessen the level of stress after removal into a new tank by putting the fish into the unlit tank.


Prefer eating blood worm, tubifex, white worms, brine shrimp. Also the fish may adjust to some small sized granules slowly going down in the water.

Keep in mind that the feed should be small, because the fish has a small mouth. Though glass catfish may also feed on some juveniles, since they do it in the wild.

Tank mates

Is a peaceful and even timid fish. They feel more comfortable in the company of some calm fish of their size.

These may be some dwarf gourami, ram cichlid, neon tetra, Kuhli loach, panda cory, yo yo loach, rummy nose tetra, serpae tetra.

There shouldn’t be any large and aggressive fishes in the tank together with glass catfish. They love a company of its kind, so we recommend to keep at least 5 of them in the tank.

However, it’s advisable to keep a school of 10-12 fish.

Gender differences: male vs female



There’s very few information about Kryptopterus bicirrhis breeding. Breeding in a tank is a very rare event, however there’s some success in it in some far east farms.

In the wild the breeding process is a seasonal one, so when simulating the rain season in a tank one may provoke female to breed.

To do this you have to decrease the water temperature up to 22-24°C and decrease the tank water level up to its half and then each day add soft (5-10%) water with some small portions.

To stimulate the breeding it’s desirable to feed the fish with large amount of live feed. Then the female scatter about several hundreds of eggs on the tank plants.

After the breeding is over you should remove fish-parents from the tank. Simulation of the rain season will help the eggs to grow. Start feed for the juveniles is encapsulated brine shrimp.

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.