A pregnant glass catfish or Kryptopterus vitreolus is a rare sight in captivity. But it is still possible to breed this fish in your tank. In this article, you will learn about these translucent catfish, including how to care for them.

Can Glass Catfish Get Pregnant in Captivity?

Yes, this transparent catfish can get pregnant in your freshwater aquarium. Yet, you rarely see them doing so in captivity. This is mainly because they have strict conditions you must adhere to. But, with the proper care and conditions, this catfish can produce eggs every year.

Often, this fish breeds during the peak rainy season. So, how do you know if your catfish is pregnant or sick? Find out in the next section.

Is My Glass Catfish Pregnant?

It is easy to tell when this fish is pregnant. From the protruding abdomen and boxy appearance, you can tell that your catfish is pregnant.

It becomes easy to tell if your fish is pregnant or not at roughly a month. Keep in mind that there are other more reliable ways to determine if your fish is ready to spawn. We have summarized them below:

  • As the pregnancy progresses, you will notice a black spot appearing on the abdomen.
  • Fish prepare a birthing place for their young when close to giving birth (nesting).
  • Usually, when glass fish are pregnant, they get more attention from male fish in the aquarium.
  • Experienced aquarists report noticing pregnant female catfish struggling to swim.

Now that you’ve confirmed your fish is pregnant, the next priority should be caring for it.

A Practical Care Guide

Caring for this catfish species is not an easy task. Slight changes to the tank can lead to an onslaught of diseases that can be fatal to the pregnant fish. But don’t fret, with the proper care guide, you can successfully care for this fish.

Below you will find a few tips on how to take care of your fish during pregnancy.

– Use the Appropriate Tank Size

These fish need enough space to swim and hide. Thus, we recommend getting a community tank of at least 30-gallons. A large enough tank also allows your fish to have the necessary interaction with the other fish like Cory catfish and still feel safe. Resist the urge to go for a smaller tank as it would increase the risk of diseases and make them feel unsafe.

– Maintain Water Purity

One way to maintain water purity is to carry out frequent water changes. That way, bacteria won’t have a favorable environment to thrive. Another way is by planting trees in your tanks. Try common plants like Hornwort, Java fern and Java moss.

– Choose Other Compatible Fish

Creating the right environment for this aquarium fish involves choosing the compatible fish species. When kept with other fish species with similar care needs and temperaments, you will find this fish more active and eating more.

– Get the Water Parameters Right

This fish is most comfortable in the middle layer of the tank. Ensure that the water temperature is around 76-80 F, hardness is between 8-12 KH and optimal pH of 6.5-7.

– Maintain High Water Quality

It would be best if you also controlled the ammonia and nitrate levels. High ammonia and nitrate levels leave your pregnant fish susceptible to disease from the community.

– Choose the Right Substrate

Selecting a suitable substrate is crucial for the survival of your fish and its fry. Avoid substrates with sharp edges as they can injure the fish barbels. Instead, opt for substrates like sand and small gravel.

– Get the Waterflow Right

Another thing to consider when setting up an aquarium for your pregnant catfish is the water flow. We recommend moderate flowing water that mimics the currents in their natural habitat. Thankfully, you don’t need any unique tool to get this right.

Specific Diet

We recommend feeding your phantom catfish live foods like worms, brine shrimp, and larvae. You can also supplement with commercial fish food like pellets and flakes. The combination of this will keep your pregnant catfish healthy.

– How Much Do You Feed a Pregnant Catfish?

Ensure you feed your pregnant catfish at least once a day. Where the need arises, you can feed twice a day. Only give small amounts of food that the fish can finish in about three minutes.

Overfeeding your fish can have ugly consequences, same with underfeeding it. So play it safe with nutritious foods in small quantities.

How to Care for Glass Catfish Eggs

After your fish has spread its eggs in the tank, it is up to you to care for them. Start by moving the eggs out of the tank to a breeding tank. If the eggs remain in the tank with other fish, they will be dinner for the bigger fish.

– What To Feed Glass Fish Fry?

Once the eggs hatch, feed the fry baby brine shrimps, so they remain healthy. Other meal options include larvae and small insects.


We have answered popular questions about this unique transparent fish. We hope this helps clarify your questions about caring for this fish.

1. Are Ghost Catfish Really Catfish?

Yes. But unlike other catfish, these fish are very active swimmers. They spend most of their time in the middle of the tank. They are also very peaceful despite their active nature, so they can live with other fish. Pick out other fish of similar temperament and keep time in schools of at least five.

2. How Long Do Ghost Shrimps/ Catfish Live?

Ghost shrimps can live for eight years in captivity. But their lifespan can be shortened by poor care and tank conditions. Ensure that you provide them with pristine water and follow the above recommendations.

3. What Is the Average Size of a Glass Fish?

The average glass or phantom catfish size is around 4-6 inches. Of course, the actual size of your fish depends on its genetics and the quality of care it gets from you. At four inches, this fish is big because many other transparent catfish are on the smaller side.

4. Are Glass Catfish Hardy?

No, this glass catfish breed is not as hardy as other freshwater fish. They must be kept in a spacious rank with strict water conditions; else, they will fall prey to diseases. Stick to moderately soft or mildly hard water. Ensure the pH is around 6.0-7.5 and a temperature of no more than 82 F, and your fish will be fine.

5. Can You Raise Transparent Catfish Alone?

Yes, you can keep these catfish alone in the tank. However, for best results, we advise that you keep them with other fish. Ensure that they have similar temperaments and needs so that none suffers. Swordtail catfish, mollies, marbled hatchets and tetras are good examples of compatible tank mates.

6. How Do You Breed Transparent Catfish?

Getting this fish to breed in captivity is challenging but not impossible. The first step is learning how they spawn in the wild and mimicking the conditions in your tank. That sounds hard, but thankfully, we have a way around it.

Add very little amount of fresh water into your tank daily. Remember to feed them with more live foods than dried food. If you follow all of our tips, you will have little catfishes swimming in your tank in no time at all.


Glass or transparent catfish are unique fish species that rarely breed in captivity. We have outlined what you should do if your fish is pregnant.

  • Breeding this catfish is difficult but not impossible
  • Mimic the conditions in its natural habitat during the rainy season, and this fish will breed
  • The protruding abdomen and dark spot on their back give away the pregnant ghost fish
  • On close inspection, you can spot the tiny eggs in the fish’s abdomen

We hope this article has answered some of your questions about this catfish and how to care for them. If you have any other questions, please drop them in the comment section.

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