Glass Catfish (Kryptopterus vitreolus): Ultimate Care Guide

Common Name(s)Glass Catfish, Ghost Catfish, X-Ray Catfish, Phantom Catfish
Scientific NameKryptopterus Vitreolus
Temperature75F – 80F
Water pH6.5- 7.0
Sizeup to 6 inches

Glass Catfish Facts

  • Glass Catfish are a popular freshwater pick for the home aquarium due to their translucent coloration. You can see right through their bodies to their organs underneath their scales.
  • Glass Catfish use their coloration to their advantage as it renders them virtually invisible to predators.
  • Glass Catfish are schooling fish. They swim and eat in a school. They do not do well alone, and have to be kept in a minimum grouping of at least 5 Glass Catfish.

The most distinguishing feature of the Glass Catfish is their transparent color, and almost completely see-through aside from some black markings around their faces. They have small, black eyes, and long barbels that extend outward. Their barbels help them locate food in the water and in the substrate, while their transparent coloration helps them avoid predators. From a distance Glass Catfish are virtually invisible. It is quite shocking to look at them because you can see their internal organs and even their spinal cord through their skin.

Glass Catfish
Glass Catfish

Glass Catfish Care

Glass Catfish are not the easiest fish to care for, nor are they the hardiest fish that you can keep as they don’t do well with changes in their water parameters. The best way to care for Glass Catfish is to make sure that their care remains consistent. Establish a regular cleaning routine, monitor their water parameters frequently, and perform regular water changes to make sure that their tank remains suitable for them.

Tank Requirements

Glass Catfish do not do well when kept alone, and must be kept in a group of at least 5 in the same tank together. A small grouping of 5 Glass Catfish requires a tank of at least 30 gallons or more if you have the space. Each additional fish that you add to the school after that, you also need to add 5 more gallons to the tank. This will keep your tank from overcrowding. Glass Catfish do best when kept at a steady temperature of 75F, but they can tolerate a temperature range slightly warmer up to 80F and 6.5 to 7.0 pH. Due to their sensitivity, they do not do well with large changes in their water parameters, and you should establish a regular water changing routine as well as perform regular water checks to ensure that they are being kept in the correct water conditions.

Food and Diet

Glass Catfish are omnivorous. This means that they eat both plant and animal matter. In the wild, their diet consists of zooplankton, small worms, and invertebrates. They also sometimes eat insect larvae and small guppies. Even though they are omnivorous, Glass Catfish prefer meaty foods over plants. In captivity, their diet should closely mimic what they would eat in their natural habitat. Glass Catfish will adapt and eat flaked or pelleted foods, but to offer them a diet closer to what they would consume in the wild, you will need to offer them meaty foods often as well. You can give them frozen, live, or freeze dried tubifex or bloodworms as well to make sure that their nutritional needs are being met.

Glass Catfish are anxious fish, and you might find that they are absent during feeding time. This could be because they are anxious. To coax them to come out to eat, you will want to feed them closer to their hiding spot. Glass Catfish should be fed once a day, and you will want to make sure that you are feeding each fish. It is not detrimental to this species if they are fed a little more food at feeding time, but make sure to clean up any mess that they leave behind so that their water parameters are not affected.

Glass Catfish (Kryptopterus vitreolus)
Glass Catfish (Kryptopterus vitreolus)

Glass Catfish Size and Lifespan

Glass Catfish are relatively small fish that only grow up to 6 inches at full maturity. Some Glass Catfish only reach around 4 inches in length at full maturity. Their final length is greatly impacted by not only their genetics, but by the quality of care that they receive. This same rule applies to their lifespan. Glass Catfish live in captivity for up to 7 to 8 years. If they are kept in the correct setup, with regular water checks and changes, your Glass Catfish will grow larger and live longer than fish that are not.

Glass Catfish Tank Setup

When setting up an aquarium for Glass Catfish, you will want to keep in mind that they do best when kept in a school of at least 5 fish. Once you have determined the size of the school you want to keep, you then need to make sure that you have the appropriate sized aquarium. Glass Catfish require at least a 30 gallon tank for a small school of 5 fish. You will want to add an additional 5 gallons per fish after that to prevent overcrowding. Glass Catfish are an active but anxious fish. They need plenty of places to roam, but also plenty of places to hide and destress.

Glass Catfish get their food from the water around them as well as rooting through the substrate for it. A fine, sandy substrate will work best as it is soft enough to not damage the Glass Catfish’s sensitive barbels. In the wild, Glass Catfish use their transparency to help them blend into the background of their natural environment as a type of camouflage. They can be found hiding amongst the leaf litter and debris. Even though they hide amongst the debris, they do not eat it, and they will do well in an aquarium that is heavily planted. A densely planted aquarium with minimal lighting is best for Glass Catfish to help them feel right at home.

Glass Catfish are active fish, and this means that they can jump out of their tank. You will want to make sure that you have a secure lid to prevent them from jumping out.

Glass Catfish Breeding

There is not a lot of information about breeding Glass Catfish in the home aquarium. It has been done successfully, but not many times. The breeding habits of the Glass Catfish has not been documented very well in the wild. If you wish to attempt to breed Glass Catfish for yourself, you will want to take into consideration their habitat in the wild. To ensure the survival and success of the fry, you will want to set up a dedicated breeding tank for the Glass Catfish, and make sure that it is heavily planted.

During the wettest season, Glass Catfish spawn in their natural habitat. You can replicate this in your breeding tank by adding in small amounts of freshwater at a slightly lower temperature. During this time you should amp up their feeding schedule and feed them foods that are high in protein up to 3 times per day as this too mimics their natural environment. During the rainy season, there would be lots of food for them available.

When Glass Catfish males and females are getting ready to pair off and spawn, you will see them facing each other and rubbing their barbels together. If you see this happening, that is a sign that you are headed in the right direction to getting them to spawn.

How Do Glass Catfish Breed?

Glass Catfish are an egg scattering species of fish. There is not a lot known about their exact breeding rituals. When the males and females are ready to spawn, they pair off. If you see them facing each other and touching their barbels together that is a good sign that they will spawn. There is not much known about their exact breeding rituals as it has not been studied in depth. When the female is ready, she will deposit her eggs on plant leaves, while the male will come along after and fertilize them. Glass Catfish eggs take up to 4 days to hatch, and once they emerge from their eggs, they are able to eat live food.

Glass Catfish parents provide no parental care to their offspring, and have been known to eat their own eggs and fry. To ensure the survival of the Glass Catfish fry, you will want to set them up in a dedicated breeding tank. This way you can remove parent fish after they have laid their eggs.

How Do Glass Catfish Lay Eggs?

Glass Catfish are an egg scattering species. This means that the female Glass Catfish will lay her eggs in many places opposed to just one. Glass Catfish females prefer to lay their eggs on large plants and leaves.

How to Tell the Difference Between Male and Female Glass Catfish

It is very difficult to tell the difference between male and female Glass Catfish juveniles. It is much easier to wait until they have reached full maturity. Female Glass Catfish will have a more rounded belly compared to the male, and she will also have a slightly larger body.

Glass Catfish Disease

Glass Catfish are susceptible to many of the same diseases as all freshwater fish. Like most captive fish, their health is directly related to how well they are kept. If they are  not kept in the correct water parameters, then they will decline quickly. Stress, overcrowding, overfeeding, and dirty water conditions can all make your Glass Catfish become ill rather quickly. It is better to prevent ailments from happening than it is to cure them when they do. It is important to make sure that your Glass Catfish are well kept.

Common Diseases For Glass Catfish

Some of the more common ailments to glass catfish include:


Ich is a parasitic disease that affects the skin of the fish and can be identified by white spots on their body. If caught early enough, it can be treated. If it is left untreated it will spread, and eventually clog the gills of the fish and suffocate it.

Fin Rot

Fin rot is an infection in the fins of the body of the fish. If caught early it can be treated. Fin rot does exactly what the name suggests and rots away pieces of the fins of the affected fish.


Dropsy is the buildup of liquid inside the body of the fish. This can lead to the appearance that the scales are popping out or protruding from the body of the fish. In some cases, Dropsy is just a symptom of another problem. Dropsy can be treated if caught early on.


Lice in fish is very different from lice in humans. Fish lice are little crustacean-like parasites that live on the body of the fish. Not only do they cause physical damage to the fish, they can also affect the growth rate of the fish.

Why is my Glass Catfish Laying on the Bottom of the Tank?

Unfortunately, if your Glass Catfish is lying on the bottom of your tank, chances are that it has passed away. Glass Catfish are very sensitive when it comes to their needs, and if they are not being met they will not thrive. A solitary Glass Catfish will be stressed all the time, and will most likely pass away from starvation as it will not eat. They are sensitive, and not recommended for beginners to the fish keeping hobby as they can quickly become ill if their water parameters are even slightly out of balance.

Are Glass Catfish Aggressive?

Glass Catfish are not considered aggressive, and they do well in community tank setups provided that they are still being cared for properly. Glass Catfish are anxious fish that will quickly become ill when stressed.

Are Glass Catfish a Schooling Fish?

Glass Catfish are schooling fish. They have to be kept in a small grouping of at least 5 to keep happy. They can not be kept by themselves as they will be too anxious to eat and starve themselves.

How Many Glass Catfish Should Be Kept Together?

Glass Catfish should be kept in a school of at least 5 fish or more. You will want to keep 5 Glass Catfish in a tank that is roughly 30 gallons, and add an additional gallon for each fish you add to their school.

Can Glass Catfish Live Alone?

Glass Catfish need to be kept in a school. They can not live alone as they will be too anxious and will not come out of hiding, even to eat. They will eventually die from stress, starvation, or some other ailment brought on by stress.

Glass Catfish Tank Mates

Glass Catfish are peaceful fish that are compatible with a variety of other community fish. Here are a few common tank mates to consider, as well as their level of compatibility.

Glass Catfish and Shrimp

It is possible to keep Glass Catfish and Shrimp together. You will want to keep in mind the size ratio of the two species. You will want to house shrimp that are roughly the same size as a fully mature Glass Catfish. Otherwise, the Glass Catfish may see the shrimp as food.

Glass Catfish and Guppies

Guppies are not a good idea to keep with Glass Catfish as they will seek them out for food. In their natural habitat, Glass Catfish often feed on guppies.

Glass Catfish and Angelfish

It is possible to keep Glass Catfish and Angelfish together in the same tank, but you will need to be mindful of the activity of the other fish in the aquarium. If there is too much going on, and your community tank is too active, it is not a good choice for Glass Catfish. Glass Catfish stress out easily, and they will hide until they starve themselves if they are not comfortable with their surroundings.

Glass Catfish and Neon Tetra

Neon Tetras are a good choice for a non-confrontational tank mate for a Glass Catfish. They occupy different levels in the water column, and typically their activities do not disturb one another enough for it to matter. Just make sure that they are being fed correctly and that there is not a competition for food.

Glass Catfish and Betta

If the tank has been set up correctly with plenty of places for Glass Catfish to hide and get away, you might potentially be able to house these two species together. Another way to ensure their success is to find a Betta that has a relatively calm temperament.

Glass Catfish and Goldfish

Goldfish are not a good choice to try and house with Glass Catfish. They do not share the same water parameters, and goldfish produce a lot of waste that could potentially cause harm to the Glass Catfish.

Where Can I Find Glass Catfish For Sale?

If you are looking to purchase Glass Catfish for your home aquarium, you will be able to find them available for sale online from breeders, and some pet stores. You can expect to pay around $10 for a small school of 5.

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