Photo: JC7001 (CC BY-SA 2.0) — via Wikimedia Commons
Giant Glass Catfish (Kryptopterus bicirrhis)
A gracefully transparent schooling catfish from Southeast Asian rivers — larger and bolder than the common glass catfish, with trailing barbels that almost reach its tail.
Will it live with a Giant Glass Catfish?
We compare each fish against your giant glass catfish on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Banded Gourami✅ CompatibleSemi-aggressive · 12 cm · Easy care · 22–28 °C (72–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 22–27 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Banjo Catfish✅ CompatiblePeaceful · 15 cm · Medium care · 20–26 °C (68–79 °F)
- Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
- Bearded Corydoras✅ CompatiblePeaceful · 10 cm · Medium care · 18–24 °C (64–75 °F)
- Compatible on the things that matter: shared water near 22–24 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Bearded Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Blue Gourami✅ CompatibleSemi-aggressive · 13 cm · Easy care · 22–28 °C (72–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 22–27 °C — no size, zone or temperament conflicts.
- Boesemani Rainbowfish✅ CompatiblePeaceful · 11 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 24–27 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Boesemani Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Bristlenose Pleco✅ CompatiblePeaceful · 12 cm · Easy care · 23–30 °C (73–86 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Clown Rasbora✅ CompatiblePeaceful · 10 cm · Medium care · 23–28 °C (73–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Clown Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Cupid Cichlid✅ CompatibleSemi-aggressive · 12 cm · Medium care · 24–29 °C (75–84 °F)
- Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Giant Betta✅ CompatiblePeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 24–27 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Giant Kuhli Loach✅ CompatiblePeaceful · 12 cm · Easy care · 24–30 °C (75–86 °F)
- Both are peaceful, and their water overlaps around 24–27 °C — no size, zone or temperament conflicts.
- Golden Vampire Pleco✅ CompatibleSemi-aggressive · 11 cm · Medium care · 26–30 °C (79–86 °F)
- Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 26–27 °C — no size, zone or temperament conflicts.
- Marbled Hoplo✅ CompatiblePeaceful · 14 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Medusa Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 26–30 °C (79–86 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Moonlight Gourami✅ CompatiblePeaceful · 15 cm · Easy care · 25–30 °C (77–86 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Murray River Rainbowfish✅ CompatiblePeaceful · 11 cm · Easy care · 15–26 °C (59–79 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Murray River Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Pearl Gourami✅ CompatiblePeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 24–27 °C — no size, zone or temperament conflicts.
- Polka-dot Loach✅ CompatibleSemi-aggressive · 13 cm · Medium care · 24–28 °C (75–82 °F)
- Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
- Rubber Lip Pleco✅ CompatiblePeaceful · 12 cm · Easy care · 20–26 °C (68–79 °F)
- Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
- Spotted Rubbernose Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 20–26 °C (68–79 °F)
- Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
- Spotted Talking Catfish✅ CompatiblePeaceful · 15 cm · Easy care · 22–26 °C (72–79 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Striped Eel Loach✅ CompatiblePeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
- Swordtail✅ CompatibleSemi-aggressive · 14 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 22–27 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- T-bar Cichlid✅ CompatibleSemi-aggressive · 12 cm · Medium care · 22–28 °C (72–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 22–27 °C — no size, zone or temperament conflicts.
- Tiger Betta✅ CompatibleSemi-aggressive · 11 cm · Hard care · 22–27 °C (72–81 °F)
- Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Angelfish⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
- Angelfish and Giant Glass Catfish are close in size, but the semi-aggressive one tends to dominate — add giant glass catfish in a group to spread the pressure.
- Blue Flash Cichlid⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 24–28 °C (75–82 °F)
- Expect Blue Flash Cichlid to harass Giant Glass Catfish at times; give dense cover and watch them at feeding.
- Your 120 L tank is below the ~210 L this pairing really wants — crowding raises aggression.
- Bumblebee Cichlid⚠️ With cautionAggressive · 15 cm · Medium care · 24–28 °C (75–82 °F)
- pH preferences only just meet (Giant Glass Catfish 6.5–7.5 vs Bumblebee Cichlid 7.8–8.6) — target the overlap and acclimate slowly.
- Bumblebee Cichlid and Giant Glass Catfish are close in size, but the aggressive one tends to dominate — add giant glass catfish in a group to spread the pressure.
- Your 120 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Clown Barb⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
- Expect Clown Barb to harass Giant Glass Catfish at times; give dense cover and watch them at feeding.
- Your 120 L tank is below the ~132 L this pairing really wants — crowding raises aggression.
- Keep Clown Barb in a shoal of 6+ or it gets stressed and nippy.
- Denison Barb⚠️ With cautionPeaceful · 15 cm · Medium care · 18–25 °C (64–77 °F)
- Your 120 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Keep Denison Barb in a shoal of 6+ or it gets stressed and nippy.
- Dolphin Cichlid⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 23–28 °C (73–82 °F)
- Expect Dolphin Cichlid to harass Giant Glass Catfish at times; give dense cover and watch them at feeding.
- Your 120 L tank is below the ~208 L this pairing really wants — crowding raises aggression.
- Electric Blue Acara⚠️ With cautionSemi-aggressive · 16 cm · Medium care · 22–28 °C (72–82 °F)
- Expect Electric Blue Acara to harass Giant Glass Catfish at times; give dense cover and watch them at feeding.
- Emperor Peacock Cichlid⚠️ With cautionSemi-aggressive · 16 cm · Medium care · 24–28 °C (75–82 °F)
- pH preferences only just meet (Giant Glass Catfish 6.5–7.5 vs Emperor Peacock Cichlid 7.6–8.6) — target the overlap and acclimate slowly.
- Emperor Peacock Cichlid and Giant Glass Catfish are close in size, but the semi-aggressive one tends to dominate — add giant glass catfish in a group to spread the pressure.
- Your 120 L tank is below the ~210 L this pairing really wants — crowding raises aggression.
- Eureka Red Peacock Cichlid⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 24–28 °C (75–82 °F)
- Different pH ranges (6.5–7.5 vs 7.8–8.6); doable if you sit in the shared band, but not ideal long-term.
- Expect Eureka Red Peacock Cichlid to harass Giant Glass Catfish at times; give dense cover and watch them at feeding.
- Your 120 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Firemouth Cichlid⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 22–29 °C (72–84 °F)
- Firemouth Cichlid is semi-aggressive and may chase or nip the smaller Giant Glass Catfish — plant heavily and break up sight lines.
- Your 120 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Gold Zebra Loach⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 25–29 °C (77–84 °F)
- Gold Zebra Loach and Giant Glass Catfish are close in size, but the semi-aggressive one tends to dominate — add giant glass catfish in a group to spread the pressure.
- Your 120 L tank is below the ~130 L this pairing really wants — crowding raises aggression.
- Green Phantom Pleco⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 26–30 °C (79–86 °F)
- Green Phantom Pleco and Giant Glass Catfish are close in size, but the semi-aggressive one tends to dominate — add giant glass catfish in a group to spread the pressure.
- Your 120 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
- Jewel Cichlid⚠️ With cautionAggressive · 15 cm · Medium care · 22–26 °C (72–79 °F)
- Expect Jewel Cichlid to harass Giant Glass Catfish at times; give dense cover and watch them at feeding.
- Your 120 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
- Panama Convict Cichlid⚠️ With cautionAggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
- Expect Panama Convict Cichlid to harass Giant Glass Catfish at times; give dense cover and watch them at feeding.
- Your 120 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
- Snowball Pleco⚠️ With cautionPeaceful · 16 cm · Medium care · 24–30 °C (75–86 °F)
- Your 120 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
- Yoyo Loach⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
- Expect Yoyo Loach to harass Giant Glass Catfish at times; give dense cover and watch them at feeding.
- Amano Shrimp⛔ Not recommendedPeaceful · 5 cm · Easy care · 18–28 °C (64–82 °F)
- Giant Glass Catfish will hunt and eat Amano Shrimp — keep shrimp only with small, peaceful, non-predatory fish.
- Cherry Shrimp⛔ Not recommendedPeaceful · 3 cm · Easy care · 18–28 °C (64–82 °F)
- Giant Glass Catfish will hunt and eat Cherry Shrimp — keep shrimp only with small, peaceful, non-predatory fish.
- Keep Cherry Shrimp in a shoal of 10+ or it gets stressed and nippy.
- Crystal Red Shrimp⛔ Not recommendedPeaceful · 2.5 cm · Hard care · 20–24 °C (68–75 °F)
- Giant Glass Catfish will hunt and eat Crystal Red Shrimp — keep shrimp only with small, peaceful, non-predatory fish.
- Keep Crystal Red Shrimp in a shoal of 10+ or it gets stressed and nippy.
- Discus⛔ Not recommendedPeaceful · 20 cm · Hard care · 28–31 °C (82–88 °F)
- Temperature needs don't overlap (Giant Glass Catfish 22–27 °C vs Discus 28–31 °C).
- Your 120 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Keep Discus in a shoal of 6+ or it gets stressed and nippy.
- Ghost Shrimp⛔ Not recommendedPeaceful · 4 cm · Easy care · 18–28 °C (64–82 °F)
- Giant Glass Catfish will hunt and eat Ghost Shrimp — keep shrimp only with small, peaceful, non-predatory fish.
- Keep Ghost Shrimp in a shoal of 6+ or it gets stressed and nippy.
- Tiger Shrimp⛔ Not recommendedPeaceful · 3 cm · Hard care · 20–25 °C (68–77 °F)
- Giant Glass Catfish will hunt and eat Tiger Shrimp — keep shrimp only with small, peaceful, non-predatory fish.
- Keep Tiger Shrimp in a shoal of 6+ or it gets stressed and nippy.
Compatibility is computed from each species' care data — a strong starting point, not a guarantee. Individual temperament varies, so always introduce new fish slowly and watch them.
Giant Glass Catfish care specs
- Care level
- Medium
- Breeding
- Very Hard
- Max size
- 15 cm (5.9 in)
- Min tank size
- 120 L (31.7 gal)
- Temperature
- 22–27 °C (72–81 °F)
- pH
- 6.5–7.5
- Hardness
- 2–12 dGH
- Lifespan
- 5–8 years
- Diet
- Carnivore
- Swim level
- Middle
- Group size
- 5+ (shoaling)
- Family
- Siluridae
- Origin
- Southeast Asia — Mekong and Chao Phraya basins, Sumatra, Borneo
What is a Giant Glass Catfish?
The giant glass catfish (Kryptopterus bicirrhis) is a mid-water schooling catfish from the rivers of Southeast Asia, prized for its completely transparent body that reveals the spine and internal organs in striking detail. Reaching up to 15 cm (6 in), it is substantially larger than its more commonly sold relative Kryptopterus vitreolus and carries two long, whisker-like barbels that stream behind it as it hovers against a gentle current.
Schools of five or more move in loose synchrony, facing into the flow — a genuinely unusual display that few community fish can match. The body catches light at different angles, shifting from near-invisible to a flash of silvery-blue iridescence depending on how the light hits it. For fishkeepers who want something striking and peaceful in a planted community tank, the giant glass catfish delivers on both counts — provided you can meet its water quality and social requirements.
Where do Giant Glass Catfish come from?
In the wild, K. bicirrhis is found across a broad sweep of mainland and island Southeast Asia: the Mekong and Chao Phraya river systems in Thailand, as well as river drainages in Sumatra and Borneo. These habitats are typically clear, moderately fast-flowing rivers and large streams with good oxygen levels, a sandy or silty substrate, and abundant vegetation and submerged wood along the margins.
Water chemistry in these systems tends toward the soft and slightly acidic to neutral end of the scale — conditions the fish seeks out where tributary inputs keep hardness low. Understanding this origin explains why the species struggles in hard, alkaline tap water that suits many other community fish. Recreating even a rough approximation of soft, well-oxygenated, mid-current conditions pays off immediately in feeding confidence and schooling behaviour.
What size tank does a Giant Glass Catfish need?
The minimum is 120 litres (32 gallons), and a long-footprint tank is far preferable to a tall one. This species schools actively in the middle water column and needs horizontal swimming space. A standard 120 cm (48 in) long tank gives a school of five room to form and orient naturally; anything shorter creates congestion and stress.
A key hardware consideration is flow and oxygenation. Giant glass catfish are adapted to moving water and need more surface agitation than most community fish. A canister or hang-on-back filter positioned to create a mid-level current works well; powerheads can supplement flow in larger setups. Avoid dead spots. The tank should be covered — these fish are capable jumpers, especially when startled.
Decor should combine open midwater swimming lanes with shaded refuge zones. Dense plantings at the sides and back, driftwood and floating plants to diffuse overhead light, and a dark substrate all contribute to a tank where the fish feel secure enough to school openly rather than hide.
What water parameters do Giant Glass Catfish need?
- Temperature: 22–27 °C (72–81 °F). This is a slightly cooler range than many tropical species; avoid the upper end long-term.
- pH: 6.5–7.5. Soft to neutral is the target; strongly alkaline water above pH 7.5 is stressful.
- Hardness: 2–12 dGH. The softer end of this range is preferable; very hard water is a chronic stressor.
Water quality must be genuinely good, not just chemically correct. K. bicirrhis is sensitive to elevated nitrates and any ammonia or nitrite in the water column. Weekly partial water changes of 25–30 % are a baseline; ensure the tank is fully cycled before any fish are introduced. If your tap water is hard and alkaline, consider blending it with reverse-osmosis or rainwater to bring parameters into range before continuing.
What do Giant Glass Catfish eat?
Giant glass catfish are strict carnivores that strongly prefer moving prey. In the wild they intercept invertebrates and small fish in the current; in captivity the closest equivalent is live or frozen bloodworms, brine shrimp, daphnia and mosquito larvae. These should form the backbone of the diet.
Newly acquired fish frequently refuse to eat for the first week or two while they settle in. A school of five or more in a dark, planted tank almost always shortens this refusal period significantly — fish that feel safe eat. Once established, some individuals can be transitioned to high-quality sinking carnivore pellets, but this is not guaranteed, and flake food is rarely accepted. Feed small amounts once or twice daily, remove uneaten food within a few minutes, and vary the frozen menu to keep nutritional bases covered.
Are Giant Glass Catfish peaceful — and what fish can live with them?
K. bicirrhis is peaceful toward any fish it cannot swallow. The main risk runs the other way: nippy or boisterous tank-mates quickly destroy the calm that this skittish species needs. Avoid tiger barbs, serpae tetras and similar fin-nippers. Aggressive or territorial cichlids are equally problematic.
Good companions share the soft, warm-water preference and a non-aggressive temperament. Classic pairings include smaller rasboras (harlequin, chili), cherry barbs, cory catfish and other peaceful bottom-dwellers, and similarly sized peaceful characins. Keep in mind that the giant glass catfish occupies the middle water column, so bottom-dwellers complement rather than compete with it.
Critically, K. bicirrhis must be kept in a school of at least five. Solo specimens or pairs become chronically stressed, stop eating, and rarely survive long. A larger school of seven or more produces more confident, visible schooling behaviour.
For a full breakdown of compatible and incompatible species, see Giant Glass Catfish tank mates.
How do you tell male from female Giant Glass Catfish?
There is no reliable external difference between males and females under normal conditions. Sexing by external examination is not practical for aquarists. The only visible indicator is that gravid females may appear slightly fuller-bodied in the abdominal region when carrying eggs, but this is subtle and only apparent in well-conditioned adults in breeding condition. For most community-tank purposes, sexing is not necessary — purchase a group of six or more from the same stock and the odds are reasonable that both sexes are represented.
Can you breed Giant Glass Catfish?
Breeding in captivity is rated very hard and has been achieved only rarely, typically in dedicated breeding setups outside the community tank. There are no documented reports of reliable aquarium breeding at the time of writing; most fish in the trade are wild-caught.
What is known from the few recorded spawning events is that conditioning with heavy live-food feeding, a gradual drop in temperature to the lower end of the range (around 22 °C / 72 °F), and a slight increase in current appear to be relevant triggers. Soft, acidic water is assumed to be essential. The eggs and fry are tiny and require infusoria or similarly fine first foods. Given the very hard difficulty rating, this is a challenge for experienced specialist breeders rather than a project for the general community-tank keeper.
What diseases affect Giant Glass Catfish?
Like many scaleless or thin-skinned species, K. bicirrhis is more susceptible to ich (Ichthyophthirius multifiliis, presenting as white salt-like spots) and velvet (Oodinium) than robust scaled fish, and reacts poorly to standard medication doses. Other concerns include bacterial infections (open lesions, fin deterioration) and internal parasites in wild-caught individuals — which most stock is.
Prevention is by far the most effective approach:
- Quarantine all new arrivals for three to four weeks in a separate tank before they enter the community display.
- Maintain pristine water quality; elevated nitrates are a primary stressor that opens the door to opportunistic disease.
- Avoid sudden temperature or chemistry swings.
- Feed a varied, nutritious diet to keep immune function high.
- Observe the school daily — a fish that hangs at the back, tilts slightly, or stops joining the school is often the first warning sign.
Health note: medication dosing and disease diagnosis are beyond the scope of a care profile. Scaleless catfish species are sensitive to many common treatments; confirm diagnosis with a reputable fish-health or veterinary source and use appropriate species-safe medications at correct doses before medicating.
How long do Giant Glass Catfish live?
A well-kept K. bicirrhis lives 5–8 years in a stable, correctly maintained aquarium. Wild-caught fish may arrive with internal parasites or transport stress that shortens this if not addressed in quarantine. Those that clear quarantine in good condition and settle into a properly set-up tank — soft water, strong schooling group, live and frozen diet, low nitrates — can reach the upper end of that range without difficulty. The lifespan reflects a species that is not inherently delicate but is genuinely unforgiving of poor water quality and social isolation.
Frequently asked questions
Is the giant glass catfish the same as the common glass catfish?
No. The common glass catfish sold in most fish stores is Kryptopterus vitreolus, which tops out at around 8 cm. Kryptopterus bicirrhis is a larger species reaching 15 cm, with noticeably longer barbels and a slightly more robust build. Both are transparent, but K. bicirrhis needs a bigger tank and stronger current.
Why do giant glass catfish refuse to eat?
They are strict carnivores that prefer moving prey. Offer live or frozen bloodworms, daphnia and brine shrimp to start; once settled they often accept high-quality frozen foods. They rarely take flake or pellets. A dark, planted tank with gentle flow and a school of five or more reduces stress and improves feeding response.
What you need to keep a giant glass catfish
The baseline is a heated, filtered 120 L+ tank: a reliable heater to hold 22–27 °C (72–81 °F), a gentle filter that won't batter a giant glass catfish in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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