Glass Catfish: Species Profile

Category: Catfish

Common Names: Glass Catfish, Ghost Catfish

Scientific Name: Kryptopterus bicirrhis

Family: Siluridae

Minimum Tank Size: 20 Gallons

Care Level: Moderate

Temperament: Peaceful

Max Size: 3 Inches

Temperature: 74-80 F

pH: 6.5-7.0

Tank Level: Middle

Colors: Clear

Diet: Omnivore

Breeding: Difficult

Glass Catfish with Rock and Gravel

Glass Catfish Species Overview

There are over 3,400 catfish species, but when you see a glass catfish, you’ll never forget it. These unique fish have transparent scales and bodies.

All fish in the Kryptopterus family share this feature, and today the focus will be on Kryptopterus vitreolus.

Glass catfish are relatively easy to own compared to other catfish, but overall can be best for beginner to intermediate fish owners.

These fish need consistent water conditions and someone who can provide space and care for schooling fish.

Still, they’re an eye-catching addition to any tank. You’ll need time to source glass catfish, as they’re an uncommon variety.

Distinguishing Features

One primary identifier for catfish species is their long facial barbells, which mimic whiskers. Glass catfish have only two small ones but still have this hallmark feature.

You may also see glass catfish called ghost catfish or phantom catfish. These are common names for the same species, but they can occasionally be for other species in the Kryptopterus family.

Kryptopterus vitreolus has only recently gained identification as a separate species from Kryptopterus bicirrhis. Glass catfish will stay crystal clear their entire life, where Kryptopterus bicirrhis will mature and become white.

There are a few ways to identify the differences between the fish in the Kryptopterus family, but one significant feature to look for is the color of the spinal cord. True glass catfish have a clear or white spine, not black or other colors.

Due to their unique lack of coloration, you can see a glass catfish’s internal organs. With a magnifying glass, you may even be able to catch a glimpse of its beating heart.

Additionally, if you have female glass catfish, you may see them carry their eggs.

Glass catfish are one of the species of fish that have a way to detect magnetic fields for navigation and to identify prey and predators. Scientists are studying this gene to find treatments for epilepsy and Parkinson’s.

Glass Catfish in Front of Rock


Glass catfish are most commonly aquarium pets, but these fish have Asian roots. They exclusively live in Thailand’s waters, usually in river channels or streams.

Among Thailand’s rivers, they usually are south of the Isthmus of Kra and stick to warmer waters that lead to the Gulf of Thailand.

These fish typically appreciate the moving fresh water, but you may occasionally find them in standing water. The best habitats for them have plants and some places to hide with filtered light.

In their natural habitat, glass catfish can be almost impossible for predators to find in the moving water because of their scales. They use their barbels to navigate murky conditions near the riverbed.


Glass catfish are small fish, unlike their distant family members of species of catfish which can grow rather massive.

Their lean bodies are thin and can seem almost like a leaf. It’s challenging to see them without light catching the shimmer on their scales.

Ultimately your glass catfish will grow up to 4-5 inches in length, and it’s the same size as male or female catfish. These fish are so small that they often weigh less than an ounce.

Along this short length, you can see their spine and bones, and you can find all of their internal organs near their pointed heads. Their fins can be hard to spot, as they only have four.


With proper care, glass catfish will usually live 7-8 years. When they’re near death is the only time they aren’t clear, as these fish will turn white once they pass.


Unfortunately, it can be a challenge to identify female and male glass catfish. These fish don’t have many telling features that distinguish their gender.

Occasionally females may be slightly smaller than males, but this isn’t an exact tell.

One of the only ways to accurately differentiate between genders is to try and compare the fish’s abdomens. Female glass catfish will have slightly rounder, bigger bellies that form a bump, especially during sexual peaks.

If your glass catfish are mating, you’ll be able to identify the females because their eggs may be visible.

School of Glass Catfish with PlantSchool of Glass Catfish


Overall, glass catfish are a fun addition to any aquarium and make for pleasant fish to keep. They generally have a very peaceful demeanor and don’t work well with aggressive species.

The glass catfish’s peaceful nature makes them slightly skittish, especially when they’re new to your tank. Expect them to hide from sudden movements or shifts of light during the adjustment period.

Even once you’ve had glass catfish for a while, you may notice that they enjoy hiding and exploring the spaces between plants and crevices.

One singular exception to their peaceful nature is around fry fish and fish eggs, which they may attack to eat.

Many catfish stick to the bottom of aquariums, which some owners can find a bit boring. Glass catfish have more energy, and their small size helps them move around your tank more than you may expect.

These fish won’t cause any issues if you add them to a peaceful tank, but they must have other glass catfish accompanying them. A solitary glass catfish may die from isolation, even with other fish of different species.

In the wild, glass catfish form large schools. This social interaction is necessary for their happiness and survival, so you should aim for at least five glass catfish.

Luckily, the appearance of a school of glass catfish can be quite the spectacle to enjoy as small skeleton-like fish float by your eyes.

Tank Parameters

Tank parameters are all the necessary conditions you’ll need to know to keep your glass catfish happy and healthy. These tank conditions are crucial to reducing the risks of disease and death.

Keeping the habitat consistent for glass catfish is crucial, and they need large tanks with plenty of plants, which can make them slightly challenging to own.

Ensure you follow these instructions and have your tank appropriately set up before receiving the fish.

Minimum Tank Size

Glass catfish appreciate rivers and streams, and while they can naturally live in narrow areas, they require a large tank in aquariums.

The absolute minimum size of tank you can keep glass catfish in is 30 gallons. You should also have a method to keep the water moderately moving in this tank.

Ensure you have plenty of room for planting and for the school of fish to move together.

If you plan to have more than five glass catfish in your school, add five gallons of water for each additional fish.

Water Parameters

The water parameters for glass catfish are crucial. These fish can be particularly sensitive to issues with the water, and slight changes in acidity or temperature can quickly lead to illness and death.

Follow these instructions carefully, and consider looking for automated options that keep your tank well-adjusted. Additionally, prepare yourself for emergencies by having backup power sources ready for any filters or other devices necessary.

Big School of Glass Catfish


Their natural habitat is the southern river waters of Thailand, so glass catfish tend to like warmer water.

Temperature is one of the crucial water parameters that should stay within a steady range because otherwise, you may risk losing your glass catfish.

Aim to have your water’s temperature around 75-80 degrees Fahrenheit. Feel free to choose a mid-range temperature, and find the ideal temperature you can keep consistent with your available tools.


The pH of an aquarium refers to the acidity level of the water. Again, the pH is one of the parameters that must be kept consistent for glass catfish.

Some fish can tolerate slight changes, but glass fish quickly fall ill. Ensure you have a reliable way to test the acidity of your aquarium, and regularly do so with glass catfish.

Generally, glass catfish appreciate a neutral tank that leans slightly more acidic. The ideal range seems to be between 6.5 and 8.0 pH.


Finally, salinity is the last water parameter you should closely monitor. The salinity of the water is the measurement of how much salt is in the body of water.

Glass catfish have a natural habitat in freshwater rivers, so they need a low salt level. While slight changes may sicken glass catfish, salty water can quickly lead to death.

Generally, the ideal water hardness for glass catfish lies between 8-10 degrees of general hardness (dGH).

Tank Setup

The water parameters are just the beginning of setting up an aquarium for glass catfish. These fish thrive in conditions that allow them to have places to hide and explore.

One essential consideration is that after you add plants or other decorations, it might temporarily affect the water’s pH or hardness. Test your water parameters before and after setting up the tank, and don’t forget to remove fish when you’re changing your tank around.

In addition to needing a large tank to decorate, you should also have an open area for the fish to swim as they would in the middle of the river channel.

Generally, people find this part of setting up fish tanks to be fun. Enjoy letting yourself be creative when building their habitat, and follow a few basics to ensure your fish stay happy.


An aquarium substrate is a bottom layer that makes the flooring, and ideal ones have extra nutrition and stimulation for fish.

Try to mimic the natural habitat of glass catfish to achieve the best substrate for your aquarium. Riverbeds are muddy and soft, with plenty of leaf litter and other organic debris.

You can completely line the bottom of your tank with leaves, but always closely inspect and identify them and other materials before adding them to your tank. Occasionally they can leech toxins into the water.

On the other hand, good leaves will add nutrients to your water, and your fish will feel comfortable.

Keep the tone muted and natural because glass catfish don’t like much light. They’re used to navigating dark waters with their barbels, so keep sharp objects or gravel out of the tank.

Sharper gravel or large pieces can risk injuring the barbels. Soft, fine-grain sand can be the perfect base.


For decor, it’s best to keep to natural elements. These will look the best with the neutral tones of your substrate, and your glass catfish will appreciate them.

Try adding options like:

  • Driftwood
  • Twigs
  • Pinecones
  • Other organic debris

Smooth, soft rocks or other objects often found in rivers can also work.

Keep these items in the middle, background, or edges and ensure your fish have plenty of room for school swimming. Glass catfish do best with space to explore but still have small hiding areas.

Again, be very careful about adding any items to your tank to ensure you avoid cross-contamination or other issues. Remember to always fully cycle your aquarium before adding glass catfish.


Plants are a critical feature of healthy glass catfish aquariums. When planning your tank, ensure you include plenty of plants over other forms of decor.

Glass catfish enjoy hiding under the leaves of plants, as it comes naturally to them. The entire school of catfish will move as one and hide under large enough leaves.

Aquarium plants can also clean water and provide nutrients to other organisms. Additionally, glass catfish appreciate the shade they supply and will seek out their dark cover.

Some frequent options are:

  • Java ferns
  • Hornwort
  • Java moss

These delicate plants provide large growths that glass catfish enjoy exploring and hiding within. Despite their appearance, the plants are usually hard to kill.


Glass catfish prefer dim lighting because their natural habitat is dark and murky. Bright tanks can be stressful for glass catfish and may result in them perpetually hiding.

In addition to having dim lighting, part of the reason plants are necessary for glass catfish is to add light filtration and shade. Regardless of your source, ensure there are dark places for glass catfish to relax.

pehem [CC BY-SA 2.5]


A strong to moderate range is the best option filter for your glass catfish aquarium. These fish prefer well-filtered water and the best ones provide a slight current to the water.

Filters can keep the water clean, provide a current that mimics the natural river habitat, and stimulate fish when they swim.


Heating is crucial for glass catfish, as you need a powerful unit to maintain a stable temperature.

The fish prefer 75-80° F, so having a heating element that allows you to set and monitor temperature can be helpful. Ones with secondary power sources can also be beneficial for emergencies.

Glass catfish can suffer from slight temperature dips out of their range, so choose a reliable heater.


Glass catfish naturally have an omnivorous diet, but you can primarily focus on providing prey. They will also eat dried fish foods and flakes for catfish and plant varieties if you want to provide those nutrients.

They are shy fish, so you must be careful feeding them, especially in tanks with other species. Entire schools of glass catfish will eat together at once, often while hiding.

Be patient and watch as you feed them to ensure they get a chance to eat. Here are a few of the prey options glass catfish may enjoy:

  • Water fleas
  • Zooplankton
  • Brine shrimp
  • Mosquito larvae
  • Grindal worms
  • Bloodworms
  • Dried worms and shrimp
  • Daphnia
  • Moina


The breeding habits of glass catfish are only loosely known, and most successful attempts in captivation have included an injection of hormones or pre-fertilized eggs.

Glass catfish seem to breed during spring rains, so you can mimic this in your tank by gradually adding fresh water and lowering the temperature over a few days.

You should also provide multiple feedings of live prey each day to recreate the abundance of spring. If you’re successful, a male and female will touch their barbels to initiate mating.

The female glass catfish will have eggs to spread in your aquarium plants for the male to fertilize. In a few days, the eggs will hatch, and the babies will need brine shrimp or insect larvae.

Common Diseases

Glass catfish can be very sensitive to overcrowding and changes in water parameters, but they aren’t affected by any unusual diseases.

When a glass catfish becomes sick, it will begin to turn white. This sign could be a chance to isolate the fish if necessary.

As with any other aquatic species, always look for the usual aquarium diseases such as ich, dropsy, fungus, or lice.

Potential Tank Mates

While glass catfish are social among their species and need a school, they don’t usually work well with other tank mates. The presence of additional species, even peaceful ones, can make glass catfish hide.

Still, it’s not impossible to have other tank mates. Just avoid any aggressive options. Also, know that glass catfish can prey on other fish eggs or small fry fish.

They can do well in peaceful community tanks that include fish like swordtails and mollies. Some other tank mate options:

Avoid aggressive options like barbs, cichlids, and oscars.