What African Glass Catfish Are and How They Behave

African glass catfish are small, transparent freshwater fish native to West African rivers, particularly in Cameroon and Nigeria. Their bodies are nearly see-through, which makes them visually striking in an aquarium — you can observe their internal organs, spine, and swim bladder as they move through the water. They typically grow to 2 to 3 inches long and live 5 to 8 years in captivity with proper care.

These fish are schooling species, meaning they live in groups in the wild and behave most naturally in groups in captivity. A single glass catfish will hide constantly and show stress; a group of 5 to 10 will swim openly and interact with one another. They are nocturnal and most active at dawn and dusk, though they will feed during the day if food is offered. They are not aggressive toward other fish, but they will eat very small fry or shrimp.

African glass catfish are bottom and mid-water feeders. They use their barbels (whisker-like sensory organs) to search the substrate for food and to navigate in low light. Unlike many catfish, they do not have a sucker mouth and cannot cling to surfaces — they are active swimmers rather than stationary bottom-dwellers.

Key Takeaways

  • African glass catfish must be kept in groups of at least 5 to 10 fish, as solitary individuals become stressed and hide constantly.
  • A 20-gallon long tank is the minimum for a small school, with an additional 5 gallons per fish added to the group.
  • They require soft, slightly acidic water (pH 6.0 to 7.0, temperature 72 to 82°F) and moderate water flow, not strong currents.
  • Feed sinking pellets, frozen bloodworms, and small live foods like daphnia; they rarely eat floating flakes because they feed near the bottom.
  • Tank mates should be small, peaceful species; avoid large, aggressive, or fin-nipping fish that will stress the school.

Tank Size and Water Conditions

African glass catfish need space to school and move freely without crowding. A 20-gallon long tank is the practical minimum for a group of 5 to 6 fish. Add 5 gallons for each additional fish beyond that — so a group of 10 would need roughly 45 gallons. A long tank (48 inches) is preferable to a tall one because it provides more horizontal swimming room, which is how these fish naturally move through rivers.

Water temperature should stay between 72 and 82°F. They tolerate the lower end better than many tropical fish, so a heater is necessary only if your room temperature drops below 70°F consistently. pH should be between 6.0 and 7.0 — slightly acidic to neutral. They prefer soft water (general hardness below 8 dGH), though they can adapt to moderately hard water if the transition is gradual. Perform 25 to 30 percent water changes every two weeks to maintain stable conditions.

Water flow should be gentle to moderate. These fish come from slow-moving sections of rivers and streams, not fast currents. A standard aquarium filter is sufficient; avoid powerheads or strong directional flow that will exhaust them. They also appreciate low to moderate lighting — bright light causes stress. Use a timer to provide 10 to 12 hours of light per day, and include plants or décor that create shaded areas where they can rest.

Substrate, Plants, and Tank Décor

Use a fine substrate such as sand or smooth gravel. African glass catfish spend time on the bottom searching for food with their barbels, and sharp substrate can damage these sensitive organs. Sand is ideal because it mimics their natural habitat and allows them to sift through it naturally.

Live plants are beneficial and reduce stress. Java fern, Anubias, and Cryptocoryne are hardy species that tolerate the lower light these fish prefer and provide cover. Floating plants like water sprite also help diffuse light and create shaded zones. Driftwood and smooth rocks add structure without creating sharp edges. Avoid sharp decorations, plastic plants with rough edges, and open spaces that offer no shelter — glass catfish are nervous fish and need places to retreat.

Maintain some open swimming space in the middle and upper portions of the tank. These fish are not strictly bottom-dwellers and will swim at all levels, especially when schooling. A balance of open water and planted or decorated areas gives them room to move and places to hide when startled.

Feeding and Nutrition

African glass catfish are bottom feeders and rarely eat floating food. They need sinking pellets as a staple — look for high-quality sinking catfish pellets or small community pellets designed to sink. Feed once or twice daily, offering only what they will consume in 2 to 3 minutes. Uneaten food decays and fouls the water, so err on the side of underfeeding rather than overfeeding.

Supplement with frozen foods several times per week. Bloodworms, daphnia, and brine shrimp are all readily accepted and provide variety and nutrition. Thaw frozen food in a small cup of tank water before adding it to the tank — do not drop frozen chunks directly in. Live foods like daphnia or small live bloodworms are excellent if you can source them, as they encourage natural foraging behavior.

Avoid relying on flake food. These fish feed near the bottom and will not consistently rise to the surface to eat floating flakes. Flakes also break down quickly and cloud the water. A varied diet of sinking pellets and frozen foods will keep them healthy and their colors vibrant.

Compatible Tank Mates

African glass catfish are peaceful but nervous, so they do best with other small, calm species. Good tank mates include small tetras (neon tetras, cardinal tetras), rasboras, small peaceful corydoras catfish, and small peaceful loaches. Avoid large cichlids, aggressive barbs, fin-nippers, and any fish that will chase or harass the school.

Do not house them with large predatory fish such as oscars, large plecos, or large catfish species — they will be seen as food. Avoid fin-nippers like tiger barbs or serpae tetras, which will stress the glass catfish and damage their delicate barbels. Shrimp can work if the shrimp are large enough not to be eaten; small shrimp may disappear.

The key is maintaining a calm, stable community. Aggressive or erratic fish will cause the glass catfish school to hide constantly, which defeats the purpose of keeping them. If you observe constant hiding or loss of appetite, the tank mates may be incompatible and should be reconsidered.

Common Health Issues and Prevention

African glass catfish are hardy if water conditions are stable, but they are sensitive to sudden changes. The most common problems are stress-related (hiding, loss of appetite, faded color) caused by poor tank mates, overcrowding, or unstable water parameters. Maintain consistent temperature, pH, and water quality through regular testing and water changes.

Ich (white spot disease) can occur if water temperature drops suddenly or if new fish are introduced without quarantine. If you notice white spots on their bodies or gills, raise the temperature gradually to 82°F and treat with an ich medication designed for catfish — some medications can harm sensitive species, so read labels carefully. Quarantine new fish for two weeks before adding them to the main tank.

Barbel damage or erosion can occur if the substrate is too sharp or if water quality is poor. Damaged barbels will regrow if conditions improve, but prevention is easier than recovery. Use sand or smooth gravel, maintain good water quality, and avoid rough décor.

Breeding African Glass Catfish in Captivity

Breeding African glass catfish in home aquariums is difficult and rarely successful. They require very specific conditions — soft, acidic water, precise temperature control, and a separate breeding tank — that most hobbyists do not maintain. Sexing them is also challenging because their transparent bodies do not show obvious external differences.

If you are interested in breeding, research is limited and success rates are low. Most glass catfish in the hobby are wild-caught or bred in specialized facilities. For most aquarists, the goal is simply to maintain a healthy, long-lived school in a well-maintained community tank.

Frequently Asked Questions

Can I keep African glass catfish alone?

No. A single glass catfish will hide almost constantly and show signs of stress such as faded color and loss of appetite. They are schooling fish and need the presence of their own kind to feel secure. Keep at least 5 to 10 together.

Do African glass catfish need a heater?

If your room temperature stays above 70°F, a heater may not be strictly necessary, but one is recommended. They prefer 72 to 82°F, and a heater keeps temperature stable, which reduces stress and disease risk. An aquarium heater is inexpensive insurance.

Why are my glass catfish hiding all the time?

Constant hiding usually means stress. Check for aggressive tank mates, overcrowding, poor water quality, or sudden temperature changes. Ensure the group is large enough (at least 5 fish), the tank has planted areas and shade, and water parameters are stable. If hiding persists after these checks, the tank mates may be incompatible.

What do African glass catfish eat in the wild?

In their native West African rivers, they feed on small invertebrates, insect larvae, and organic debris on the river bottom. In captivity, sinking pellets, frozen bloodworms, and daphnia replicate this diet well.

How long do African glass catfish live?

With proper care — stable water conditions, appropriate tank mates, and a healthy diet — they typically live 5 to 8 years. Some individuals have been reported to live longer in well-maintained tanks.