When people hear “Catfish”, a big, dark lump of fish comes to their mind with whiskers going towards the body but the Glass Catfish is very different because it is a mesmerizing visual sight and a very playful and timid creature. It would come as a surprise but there are so many different types of catfish that according to experts, there is a catfish among every 4-5 freshwater fish.
Most people take Kryptopterus minor as glass catfish but glass catfish was included in these rare species in 2013. K. Minor are rarely seen in the fishkeeping trade while K. vitreolus is more commonly found.
“Kryptopterus vitreolus”, taken from the Greek words “kryptos” which means hidden, and “pterýgio” which means fin. This name was given to the glass catfish by the Swiss ichthyologist Maurice Kottelat in 2013. In the fishkeeping community, it is also called by other names such as “Ghost Catfish or Phantom Catfish”.
Origin of Glass Catfish
Native to the tropical Southeast Asian country of Thailand, this schooling catfish is very different compared to its brethren. It does not stay at the bottom of its habitat, resting on rocks and feeding on rotten substances, neither does it possess the aggressive qualities that other catfish do. The Glass Catfish is also not a good navigator in murky water as its brethren. These fish prefer rivers and streams as their natural habitat.
One of the most stand-out features of this timid little swimmer and the reason it is called the “Hidden Fin” is its completely transparent body. You can see through its body, hence the name. The transparent body of the Glass Catfish acts as a very effective survival mechanism, camouflaging it from predators.
Read on to learn more about this wonderful creature and how to care for the Glass Catfish in your own aquarium.
Scientific Name | kryptopterus vitreolus |
Kingdom | Animalia |
Phylum | Chordata |
Class | Actinopterygii |
Family | Siluridae |
Origin | Thailand |
Ease of Care | Moderate |
Temperament | Calm |
Appearance
The Glass Catfish is a special member of your aquarium, one that will surely catch anyone’s eye. When you look at its body, you will feel as if you are looking at an x-ray image of the fish with no dorsal fin. Clearly seeing through its body, the spine is visible from head to tail and the organs can be seen in a dark cluster behind the eyes.
The Glass Catfish have their whiskers faced forward. Experts suggest that they can use these whiskers to detect electromagnetic waves. Scientists are currently trying to understand this phenomenon and learn how to make use of this in the medical field. These whiskers help them navigate while swimming because water visibility is often quite low in their natural habitat.
This just goes to show the level of visual variation among the catfish. Let’s talk about the appearance of the Glass Catfish below.
Size:
4-6 inches. The Glass Catfish is a relatively decent-sized fish. They grow up to about 4-6 inches, which is quite a large size for a small aquarium.
Color:
The Glass Catfish does not display any color because it is completely transparent. The only colored feature on this fish is the dark grey color of its organs visible behind the eye. Those organs are the only part of its body that cannot be seen through.
Difference between Males and Females:
Having a transparent body, it is very difficult to tell if a glass catfish is a male or a female. Usually when the female starts carrying eggs is when it becomes relatively easy to differentiate between them, because the female gets plumper.
Life Span
The Glass Catfish lives up to 7-8 years. Its life expectancy, level of growth, and health depend entirely on the level of care provided. The more you provide them with an adequate healthy environment, the more they will thrive in a fish tank.
Diet
They are categorized as omnivores but the Glass Catfish displays predatory actions.
The food of their native habitat should be mimicked, down to the tiniest detail to make them feel more comfortable. Glass catfish eat plankton, larvae eggs, grindle worms, brine shrimp, daphnia, and blood worms. Along with this, strong flake or pellet food goes a long way in providing vital nutrients to the Glass Catfish.
Avoid overfeeding them because the excess waste and nutrients will result in the tank getting dirty with overgrown algae and fish waste. Another caution while feeding is to keep an eye on them to see if any other fish steals away their food.
Monitoring the eating habits of each aquarium inhabitant is important when you have a glass catfish in your aquarium because it gives a clear idea of how to feed it in the tank. Active and bold fish can be fed at one end of the aquarium and shy fish can be fed at the other end, where they will feed without any interruptions or startles.
Behavior and Temperament
Most catfish will stick to the bottom of the tank, resting on substrate or rocks but Glass Catfish are different. This type of catfish sticks to the middle and upper portion of the tank, swimming around, schooling with its fellow Glass Catfish. It is recommended to keep at least 5-6 of them together so they can thrive in their own kind and have a long, healthy lifespan.
Glass Catfish are active and jolly but they tend to mind their own business most of the time. This makes them ideal tank mates for any non-aggressive fish.

Aquarium and Water Parameters
Size:
Experts recommend a minimum size of 30 gallons for the Glass Catfish because these are schooling fish that are quite active. When speaking of the number of fish per gallon, experts recommend 1 Glass Catfish per 5 gallons so this makes about 6 per 30 gallons.
A bigger tank will allow them enough freedom to school around freely and live an active life, otherwise, they will suffer growth defects and other medical illnesses might arise if the tank is kept small. As in their natural habitat, they will form a tight social circle. This is why it is highly inadvisable to keep just one Glass Catfish because that may die out of stress.
Decor:
When it comes to the décor of the tank, one thing should be kept in mind that these are active schooling fish and they will need a lot of open space to roam around freely. It should not be too cluttered and allow free movement.
When it comes to plants, their natural habitat consists of lots of them that they use as hiding spots. So the use of plants like Hornwort or Java Moss should keep them happy and safe.
It should also be noted that these are fragile fish so anything that seems like it may cut their skin or harm them in any way must be avoided. This is why a sand substrate is preferred in a Glass Catfish tank because it is soft and will not cut or harm the fish in any way.
Equipment:
When it comes to equipment, all the Glass Catfish requires is a water flow regulator. This fish requires a moderate flow of water and under no circumstances can they survive in static water without suffering stress.

Water Parameters:
Aquarium Size | 30 gallons |
Water Temperature | 75-80-degree Fahrenheit |
Ph | 6.5-7.0 |
Water Hardness | 8-12 KH |
Size | 5 inches |
Lifespan | 7-8 years |
Water parameters for these fish are very strict, they are not just guidelines. Fluctuations in pH, temperature, or water hardness can have severely adverse effects on the Glass Catfish. They are not as easy to care for as other fish in the same category and this factor should be kept in mind before deciding to buy the Glass Catfish for your aquarium.
Water parameters should regularly be monitored because even the slightest mistake can result in casualties. This is the only thing to be watchful for, if you consider it a daunting task then it is recommended to try your luck with hardy fish first.

Tank Mates
Best Tank Mates:
The Glass Catfish has a very large list of compatible tank mates, their peaceful and timid nature helps avoid confrontations. The Glass Catfish will always mind its own business and not bother the other tank mates but it also does not know how to defend itself. When threatened, it will desperately try to swim towards a hiding spot. Community tanks work best for them as they are very friendly and active aquarium fish.
It has a very long list of compatible tank mates but, some of the best tank mates for the Glass Catfish are as follows:
- Kuhli Loach
- Cory Catfish
- Molly Fish
- Swordtails
Worst Tank Mates:
Any aggressive, even slightly larger, and violent fish is not recommended as tank mates for the Glass Catfish because they do not know how to defend themselves. Large fish might see them as food and other competitive fish might see them as competition and fight them.
How to Breed Glass Catfish?
As the Glass Catfish was only recently discovered, not much is known about the way it breeds because there is no recorded documentation of them breeding in captivity.
- In the wild, these fish breed during the rainy season, so to mimic that in a tank, some steps must be taken.
- Drop the water temperature slightly to 73 F and keep on adding very small quantities of fresh water every day to the tank. Adding water on a daily basis mimics rainfall in the aquarium.
- If you are lucky, you will observe the male and female facing each other and interacting with each other’s whiskers. It is difficult to differentiate between male and female but the female will usually have a plump belly full of eggs.
- When they mate, eggs are laid in the dense cover of plants and within 3-4 days they will hatch.
- The fry will need nutrients and proteins which can be achieved by feeding them baby brine shrimp.
- If you do witness this, be sure to record it because there are almost no recorded cases of them breeding in captivity yet.

Common Problems
Apart from the strict water parameter care, there really is nothing else to worry about. These fish do not have any common problems or diseases that they suffer from. The only things to care for would be water parameters and to ensure that a good number of them are kept in a tank so they do not feel alone and threatened.
FAQs
They are native to the South East Asian country of Thailand.
They grow to an average size of 5-6 inches.
They feed on plankton, bloodworms, and other such microorganisms.
Conclusion
This is definitely not a fish for beginners because of the strict water parameter requirements and water conditions. It will be difficult for any new aquarium hobbyists if they have not already undergone the trial and error experience in the aquarium trade.
However, if this is not your first time buying a fish and you have the basic skills required to care for such a fish then by all means do add this beautiful catfish to your aquarium. It will be a one-of-a-kind inhabitant that will make your aquarium look special. Available on any online fish store for $3-$5.
Best of luck with your aquarium!!