Glass Catfish

Kryptopterus vitreus

Also known as: Ghost catfish, Phantom catfish

Water Parameters

• Temperature: 22–26°C
• pH: 6–7.5
• Hardness (GH): 36–179 ppm (2–10 dGH)

Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.

Care Summary

One of the hobby's true oddities: a catfish with a near-transparent body, so clear that the spine and the silvery sac of internal organs are plainly visible, and which hovers in mid-water in a loose school rather than scavenging the bottom like most catfish. Glass catfish are peaceful and undemanding in their tastes but sensitive in their needs: they are social to the point of fragility, requiring a group of six or more, stable mature water, gentle current, and calm tankmates, and they react to stress or poor conditions by turning milky and fading. Most are wild-caught and arrive delicate, so they should go only into an established tank and never a new one. Given the right peaceful, planted, well-circulated setup and enough of their own kind, a shimmering school of glass catfish suspended in the current is one of the more quietly spectacular sights in freshwater keeping.

Tankmates

An exceptionally peaceful, nervous, mid-water schooling catfish that must be kept in a group of at least six, ideally more; in small numbers it hides, stops eating, and wastes away, and a lone glass catfish rarely survives long. Keep it only with calm, peaceful tankmates: small tetras and rasboras, corydoras, otocinclus, and peaceful gouramis. Boisterous or nippy fish such as tiger barbs, serpae tetras, and bettas stress it badly, and larger or predatory fish will eat it. It is a micropredator that hunts small foods in open water, so it needs a gentle current to swim against and open mid-water swimming space, with planted edges for security. Best added only to a mature, stable, established tank.

Compatible with

• Harlequin Rasbora
• Neon Tetra
• Cardinal Tetra
• Ember Tetra
• Bronze Corydoras
• Otocinclus
• Honey Gourami

Avoid keeping with

• Betta
• Tiger Barb
• Serpae Tetra
• Large Cichlids
• Fin Nippers
• Angelfish

Common Problems

• decline and death when kept in groups smaller than 6
• sensitivity as wild-caught fish, especially in new tanks
• turning milky or opaque under stress
• stress from boisterous or nippy tankmates

Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-20