Glass catfish (Kryptopterus vitreolus) — 5-6cm

Overview

Glass catfish (Kryptopterus vitreolus) stands as one of the most extraordinary freshwater species available for sale UK, captivating aquarists with its remarkable transparency that reveals the skeleton and internal organs. This peaceful shoaling catfish originates from Thailand and Southeast Asia, where it inhabits slow-moving rivers and streams with dense vegetation. Available in sizes from 5-6cm, the species reaches approximately 8cm at maturity, making it suitable for medium-sized community aquariums. The transparent body, midwater swimming behavior, and peaceful shoaling nature distinguish this catfish from typical bottom-dwelling species. Moderate care requirements suit aquarists with some experience maintaining Southeast Asian community fish, though the species' slightly delicate nature demands stable water quality and calm tankmates.

Appearance

The glass catfish showcases extraordinary transparency, with flesh so clear that the skeleton, swim bladder, and internal organs are clearly visible. The body is elongated and laterally compressed, creating a delicate, almost ethereal appearance. A faint silvery sheen overlays the transparent flesh, creating subtle iridescence under certain lighting. Two long barbels extend from the upper jaw, constantly sensing the environment. The dorsal fin is small and positioned far forward, while the anal fin runs nearly the entire length of the body. The caudal fin is deeply forked. All fins are transparent and delicate. Unlike most catfish, this species spends virtually all time in midwater zones rather than on the substrate. Overall appearance is mesmerizing and unique, creating a ghostly presence in planted aquariums with subdued lighting.

Natural Habitat

Kryptopterus vitreolus inhabits slow-moving rivers, streams, tributaries, and flooded areas throughout Thailand and adjacent regions of Southeast Asia. Natural habitats feature dense aquatic vegetation, submerged wood, overhanging riparian plants, and tannin-stained water. Water conditions are typically warm, soft, slightly acidic to neutral, and low in visibility. The species forms loose shoals that patrol midwater zones, feeding on small invertebrates, insect larvae, zooplankton, and organic particles. Dense vegetation and floating plants provide security from aerial predators. Seasonal flooding disperses populations into temporarily inundated forests and grasslands, while the dry season concentrates fish in deeper channels and pools.

Aquarium Setup

A minimum 80-litre aquarium with dimensions emphasizing length provides suitable space for a shoal of 6-8 glass catfish. Use fine sand or smooth gravel substrate and densely plant the tank with species such as Vallisneria, Java fern, Anubias, Cryptocoryne, and floating plants to create subdued lighting and visual security. Include driftwood and dried leaves to replicate natural habitats and provide tannin staining if desired. The species appreciates calm water—avoid strong currents that stress the fish or make swimming difficult. Filtration should be efficient but gentle, with sponge filters or low-flow internal filters working best. Subdued, diffused lighting suits the species and encourages confident behavior. Ensure excellent water quality, as glass catfish are sensitive to poor conditions and deteriorating parameters.

Water Parameters

Maintain temperatures between 22-27°C, with 24-26°C representing optimal conditions. The species tolerates slight variations but requires stability. pH should remain between 6.0-7.5, with slightly acidic to neutral values (6.5-7.0) ideal. Water hardness can range from soft to moderately hard, though soft to moderate hardness better replicates natural Southeast Asian conditions. Ammonia and nitrite must be undetectable, while nitrates should stay below 30 ppm through efficient biological filtration and weekly water changes of 25-30%. Glass catfish are moderately sensitive to poor water quality and abrupt parameter changes, responding with stress coloration (loss of transparency), lethargy, or increased hiding. Maintain consistency and perform regular maintenance to ensure long-term health.

Feeding

Kryptopterus vitreolus is a carnivore requiring small meaty foods. Offer finely crushed flakes or micro-pellets as the dietary foundation, supplemented with small frozen foods such as daphnia, cyclops, baby brine shrimp, and finely chopped bloodworms. Live foods are particularly relished and help condition the fish for optimal health. Feed small portions 1-2 times daily, ensuring food remains suspended in the water column or sinks slowly, as the species feeds primarily in midwater rather than from the substrate. In community tanks, monitor feeding closely to ensure the glass catfish receive adequate food, as more aggressive or faster tankmates may outcompete them. A varied diet supports health, maintains transparency, and encourages active schooling behavior.

Behaviour

Glass catfish are peaceful, social fish that form cohesive shoals constantly hovering in midwater zones. The shoal often remains motionless in loose formation, oriented in the same direction with subtle fin movements maintaining position. Activity increases during feeding periods, when the group disperses slightly to capture food particles. The species swims gracefully with delicate, almost imperceptible movements that create a ghostly, floating appearance. Glass catfish display no aggression toward tankmates and are entirely compatible with other peaceful community fish. Stress or inadequate shoal size causes the fish to hide constantly, lose transparency, or display erratic swimming. Confident shoals in well-planted tanks with subdued lighting remain more visible throughout the day.

Tank Mates

Kryptopterus vitreolus thrives alongside small, peaceful community fish that share similar water requirements. Suitable companions include small tetras (neon, cardinal, ember), rasboras, peaceful barbs, Corydoras catfish, dwarf gouramis, and other calm midwater species. Avoid large or aggressive fish, boisterous feeders, fin-nippers, or predatory species that may harass or consume the delicate catfish. Very active or competitive tankmates may intimidate glass catfish during feeding, so select companions carefully. In ideal conditions with peaceful tankmates and subdued lighting, the species displays its most natural, confident behavior and remains visible in the midwater zone.

Breeding

Breeding Kryptopterus vitreolus in home aquariums is uncommon and rarely documented. Successful spawning likely requires excellent water quality, soft and slightly acidic water, well-conditioned adults, and dense plant cover or spawning media for egg deposition. If spawning occurs, eggs are small and adhesive. Fry are tiny and require microscopic foods initially. Raising fry demands exceptional water quality and specialized feeding regimes. Most specimens in the trade are wild-caught or farm-raised, with captive breeding remaining rare among hobbyists.

Why Buy from Tropical Fish Co

Tropical Fish Co supplies healthy, active glass catfish carefully selected for excellent transparency and strong schooling behavior. We ensure all specimens are feeding confidently on prepared foods and displaying normal social behavior before dispatch. Our expert team provides detailed care guidance covering the importance of group housing, subdued lighting, calm tankmates, and water parameters. With reliable UK delivery using specialist livestock couriers, your catfish arrive safely in insulated packaging with oxygen. We support responsible fishkeeping and offer ongoing advice to help you succeed with this extraordinary transparent species. Choose Tropical Fish Co for quality Southeast Asian species and expert customer support.