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These amazingly transparent fish have become super popular with hobby aquarists. And it’s no wonder! The Glass Catfish is the perfect fish to add that special pizazz to your tank that will make everyone envious. 

Originating from the brackish waters of South East Asia in Indonesia, Vietnam, Cambodia, Malaysia, and Thailand, these fish are most at home in aquariums full of vegetation and other peaceful fish, such as the Tetras. This kind of environment mimics their natural habitat, creating a peacefully calm environment that mirrors their nature.

Species Profile overview (lifespan, size, etc.)

Sharing various common names with other species of skeleton catfish, the Glass Catfish is also known as the Phantom Catfish and the Ghost Catfish.

This popular species of aquarium fish are known as Kryptopterus vitreolus, not to be confused with the larger, more aggressive Glass Catfish known as the Kryptopterus bicirrhis. These more aggressive catfish are no longer popular among the aquarium hobbyists and have now become quite rare in the aquarium trade.

Kryptopterus means’ hidden fin,’ which refers to the Glass Catfish’s barely visible tail fin. Kryptos is Greek for hidden, and pterýgio means fin. Because of their transparent bodies, you can see their organs and bones, which makes them an exciting addition to your tank.

Typically, people tend to think of catfish as the large ugly freshwater fish that feed on the bottom of the streams and lakes. But the Glass Catfish defies that image. They still have a pair of barbels that belong to the catfish family, but these fish are not bottom feeders. They love to swim all around the tank and will school together with other Glass Catfish. 

When they are first introduced to the tank, they can be somewhat timid because of their peaceful nature. They may even stick around the bottom of the tank, hiding in the vegetation and tank decor. But within a few weeks, they will become comfortable in your tank and begin to swim around the middle of the tank. They are active swimmers and bring a fantastic liveliness to the tank.

In order to avoid bright, direct lights, these fish will hide in the tank’s vegetation and plants, so make sure they have plenty to choose from. 

If you take care of them properly, a healthy Glass Catfish can live up to eight years old.

Typical Behavior

The Glass Catfish loves to school together with other Glass Catfish, which creates a fantastic show of skeleton-looking fish swimming and dancing around your tank!

These fish are not limited to the bottom of the tank like others in its species. The Glass Catfish enjoy swimming energetically around the entire aquarium but stick mainly to the middle. They make wonderful additions to a peaceful community tank, keeping mostly to themselves or schooling together, hiding only when they have been disturbed.

Some of them can even detect an electromagnetic wave, which fascinates scientists who are trying to comprehend how this information can benefit patients with Parkinson’s and Epilepsy. They respond to the electromagnetic field because they have the Electromagnetic Perceptive Gene (EPG) protein. 

According to recent studies, the Glass Catfish may be able to help and possibly strengthen the treatment for anyone suffering from Parkinson’s disease. In the future, Parkinson’s patients might be able to receive an injection of the EPG in a specific region. This injection may help keep the tremors in check and help to control the patient’s disease.


The most apparent attribute for the Glass Catfish is its transparency, which allows you to see its skeleton and organs. Down the entire length of their body, you can see the central spinal column and their vertical ribs.

With a laterally compressed, elongated body and sub-terminal silver mouth, they have a lower jaw that protrudes a bit. It also has an extended anal fin that is large, clean, transparent, crescent-shaped, and runs the length of the Glass Catfish from the caudal fin to its head. The anal fin has approximately 48 to 55 fin rays. 

The Glass Catfish is a unique fish that lacks body pigmentation, scales, and a dorsal fin. There is a spot along their back where their dorsal fin should be that is slightly raised. The two fins that make it possible for them to swim up and down in the water column, their ventral and tail fins, are barely visible. They have long slender bodies and grow to be about five inches long.

Their transparency is not just for looks. It also serves as camouflage to keep them safe from predators. This transparency makes them hard to see, which in turn makes them harder to eat! 

Like most catfish, the Glass Catfish has the characteristic barbels on their head, which extend out from their nose and past their face. The barbels look similar to the whiskers on a cat, hence the name catfish. The barbels cause them to be remarkably sensitive to any changes in their environment.

Habitat and Tank Conditions

Originating from Thailand, the Glass Catfish lived in moderately moving streams and rivers. Without straying too far from the river and stream beds, they stay mostly in the middle of the water column. Because the water in rivers tends to be on the murky side, the Glass Catfish relies on its barbels quite heavily to keep it safe within these kinds of environments. 

Another intelligent survival adaptation is the Glass Catfish’s camouflage. Because of the transparency of its skin, it can be difficult to distinguish these fish from debris when visibility is low, and the water conditions are poor.

The Ideal Tank Conditions

It’s essential for the Glass Catfish to feel as at home in an aquarium as it would in a stream or river. These fish live up to their moniker because of their fragility when it comes to water conditions. They don’t do well with fluctuations in the pH, temperature, or any additional chemical fluctuations. If you don’t keep the water conditions within the proper parameters, they will die.

Plants and vegetation will help keep the water clean while providing hiding places for the fish, and will also feed other organisms that live in your tank, as well. The hardy Hornwort, Java Moss and Java Fern are all great choices for adding to your tank. Either sand or small gravel is preferred to the larger gravel or sharp substrates that can possibly damage their barbels.

Tank Setup (size, temperament, pH, lighting, etc.)

As mentioned above, these fish do not do well when there are fluctuations in the pH levels, temperatures, or additional chemical changes in their tank water. Tank conditions need to be just right for the Glass Catfish to stay healthy and thrive.

Water Conditions:

  • Temperatures should be between 75-80°F
  • Hardness should be between KH 8-12
  • pH should be between 6.5-7.0
  • Water flow should be moderate

Because of the stringent water conditions these fish need, they are a bit more challenging to care for than other beginner species that are easy to care for.

The Glass Catfish will thrive in a 30-gallon tank or larger. With such a large tank, they will have ample room to swim around in the middle regions of the aquarium. This size tank will also give you an abundance of space to add vegetation, plants, and decor for them to hide in if disturbed. 

How Many Can Be Kept Per Gallon?

Because they love to school together, it’s ideal to have at least six or more Glass Catfish in a 30-gallon tank, which is equivalent to keeping one Glass Catfish for every five gallons of water. They need ample space. Otherwise, you may be risking their health. 

Various diseases and growth defects can occur if your tank is overcrowded. For this situation, the saying, ‘Less is more,’ is appropriate. There are times when having less fish is better, especially if all of them are healthy and happy in their environment.

Glass Catfish Tank Mates

The Glass Catfish is the perfect addition to any community tank. Just in case you are unsure of what that means, community tanks are filled with peaceful fish of various species that live well together and are not aggressive and attack others.

Celestial Pearl Danios, Mollies, and Swordtails are the perfect tank mates for the Glass Catfish, as well as Tetras, Dwarf Gouramis, Dwarf Cichlids, Loricarids, Platies, Kribensis, Loaches, Hachetfish, Corydoras, and the Redtailed Shark. They also do well with some larger Gourami, Angelfish, and Silver Dollars

These tankmates are all peaceful fish who will not try to outcompete your Glass Catfish. They are also easy to keep and will get along great with your catfish. You could begin with them, adding more fish when you are ready.

One of the things you don’t want in your community tank is an aggressive fish. They are known to attack the peaceful, slower fish. Also, the aggressive fish will compete for food, which can cause slower fish to slowly starve to death as they struggle to find food and compete with the more aggressive fish for food.

Aggressive fish such as sharks and Tiger Barbs will not work in your community tank. The same goes for fish such as Oscars and Cichlids. These are aggressive fish that will attack your fish and eat them, as well.

It’s vital to these fish’s health and well-being to keep them together. When together, they will form intimate social groups similar to the way they do in the wild, so mimicking that is vital. Keeping only one of these Glass Catfish in your tank could lead to that fish dying from stress and unhappiness.

Diet and Food

When in their natural habitat in the wild, the Glass Catfish mainly eat invertebrates, small worms, and zooplankton. Even though they inhabit the middle of the water column, they can be selective feeders. They have been known to eat mosquito larvae and baby guppies, as well.

You can replicate their feeding environment with the use of frozen or live foods such as Moina, Brine Shrimp, Daphnia, and Grindal worms. However, in your aquarium tank, they will eat a wide variety of foods that includes flakes and pellets. You could even consider making your own fish food to ensure your fish are eating the absolute best ingredients, and they have the best diet possible.

As they eat, you will want to keep an eye on them, making sure that they are actually eating the food that you are feeding them. Also, watch for any aggressive fish that could be bullying them and competing for their food. 

Because of their timid nature, it’s vital to ensure they are eating the food that you are feeding them. Other species of fish, even the peaceful ones, can sometimes be more alert and proactive when getting to the food and eating, which could possibly scare your catfish away. 

Once you identify any fish that are causing issues during feeding, you can then take steps to ensure your catfish gets the food it needs. One thing you can do is to feed the side of the tank that has the active fish before adding any food to the other side of the tank for your catfish. Doing this ensures that the more active fish will get to eat first, and the slower, more timid fish will have plenty of time to eat on their own.

These fish will stay healthy and happy if you feed them once or twice daily. You will want only to feed them what they will eat in a couple of minutes. Make sure there is no food leftover. Overfeeding your fish can cause excess nutrients in your aquarium tank, which will lead to an infestation of bacteria and algae.


In their natural habitat, in the wild, the Glass Catfish will spawn seasonally, usually during heavy rain times. To mimic this in a tank setting, you will need to reduce the water temperature to about 73°F, while daily adding small amounts of freshwater. These conditions, the lower temperature, and the daily freshwater mimic the rainy season, making the catfish believe it’s time to breed.

When in the wild, the Glass Catfish has an abundance of live food during the breeding season, which gives them the energy they need to spawn. You will want to do the same and provide them with an abundance of live food when breeding them in your aquarium tank. 

When you have successfully bred these fish, the female will then spread the eggs all along the vegetation and plants in your aquarium. It takes about 3 to 4 days for the eggs to hatch. Although the newly hatched fry are tiny, they are still big enough to feed on baby brine shrimp.

Distinguishing the male from the female can be challenging. The male Glass Catfish are only slightly smaller than the females, with the females having a larger stomach for storing her eggs.

Glass Catfish Care Guide

The biggest challenge when taking care of the Glass Catfish is making sure the water conditions stay within the proper levels. Maintaining the strict water parameters makes these fish harder to keep healthy for novices and beginner aquarists.

In order to limit any risk or harm to your fish, you will need to make sure that you add them to an already established tank that has been cycled. There are any diseases or illnesses that are specific to the Glass Catfish, but they are susceptible to the common sicknesses that can affect aquariums, such as:

  • Ich, which is a grainy, white matter on their skin that resembles sand. It can also cause them to gasp for air at the surface of the tank.
  • Dropsy, which is the fish bloat up and their scales start protruding.
  • Fungus looks like white/gray growth on the fins.
  • Lice cause the fish to become restless and start rubbing themselves on the tank walls and other surfaces to try and remove the lice.

As mentioned previously, keeping the water parameters within the proper levels, avoiding overfeeding them, changing the water on a regular basis will go a long way to ensuring your Glass Catfish are not exposed to any of the above illnesses.

Another critical thing to remember is always to quarantine the fish you purchased prior to adding them to your community tank. The purpose of the quarantine is to observe the fish and ensure that they are not already ill.

Is a Glass Catfish Suitable for your Aquarium?

If you are a beginner aquarist, don’t be pulled in by the appeal of owning some Glass Catfish. They look easy to care for, but they are challenging and will require more work and attention that other beginner fish would.

The tank conditions must be within the proper range and water conditions or your Glass Catfish could be adversely affected. These fish can be more challenging than a beginner aquarist is ready for and they are not right for everyone. 

However, if you are an experienced aquarist and are ready to take on the challenge of keeping your Glass Catfish healthy and happy in your community tank, then they will make a great addition to your aquarium. Because of their transparency, these fish will give your tank an exciting and unique look that others will envy.

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Michele Taylor
Michele Taylor

Hello, fellow aquarists! My name is Michele Taylor, and I am a homeschool mother of six children, which includes five boys and one girl. My kids range in age from five-years-old to eighteen-years-old.

Growing up, our family had a large aquarium with angelfish, goldfish, and lots of different varieties of neons. We also had a “suckerfish” that grew to be about six inches long.

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