The Glass Catfish is a remarkable fish with a fully transparent body revealing its skeleton and internal organs. A perfect choice for community tanks.
Overview
Kryptopterus vitreolus is one of the most extraordinary freshwater aquarium inhabitants, belonging to the family Siluridae. This fish originates from the rivers and streams of Thailand, where it inhabits slow-moving waters among dense vegetation. The defining feature of the Glass Catfish is its completely transparent body, through which the spine, ribs, and internal organs are clearly visible. This effect is truly mesmerizing, especially when a school of these fish hovers in the water column like living ghosts.
Adults reach a size of 10-12 cm and live 5-7 years with proper care. These are peaceful schooling fish that must be kept in groups of at least 6 individuals — in smaller numbers they become timid, refuse food, and may die from stress. In a proper school, Glass Catfish feel confident and often swim in a tight group, hovering in place in the middle layer of the water.
Tank Requirements
A tank of at least 100 liters is required for a school of 6-8 Glass Catfish. Optimal water parameters are: temperature 24-28°C, pH 6.0-7.5, and general hardness (GH) 5-10 dGH. These fish are sensitive to sudden changes in water parameters, so stability matters more than hitting perfect values.
The aquarium should be densely planted with live plants, creating shaded areas — Glass Catfish do not appreciate bright lighting. Floating plants on the surface will help create soft, diffused light. Driftwood and plant thickets serving as hiding spots are essential. Water flow should be moderate, as these fish prefer calm waters in the wild. A dark, fine-grained substrate works best — the transparent bodies of the catfish look particularly striking against a dark background.
Feeding and Diet
Kryptopterus vitreolus are omnivorous with a preference for animal-based foods. In the wild, they feed on small invertebrates, insect larvae, and zooplankton. In the aquarium, they eagerly accept frozen bloodworms, brine shrimp, daphnia, and cyclops. Dry foods such as flakes and small pellets are also taken, but should not form the basis of their diet.
Glass Catfish are primarily active at dusk and during the night, so it is best to feed them in the evening or right after the main lights are turned off. Feeding 1-2 times daily in small portions is the optimal schedule. It is important to ensure that food does not sink to the bottom too quickly, as these fish prefer to catch their food in the water column.
Care and Maintenance
Glass Catfish are sensitive to water quality, making regular maintenance critically important. Weekly water changes of 20-25% are mandatory, and the fresh water must match the existing temperature and parameters. A good filter with gentle flow and adequate aeration are essential pieces of equipment.
Special attention should be paid to ammonia and nitrite levels — these must remain at zero. Nitrates should ideally be kept below 20 mg/l. When conditions deteriorate, Glass Catfish are among the first to show signs of stress: they lose their transparency, become cloudy in appearance, and hide. This is a reliable indicator that something is wrong with the water.
When moving fish to a new tank, acclimation should be performed slowly using the drip method over 1-2 hours. Sudden changes in conditions can cause shock.
Compatibility
Kryptopterus vitreolus make excellent companions for peaceful fish of similar size. Great tankmates include Neon Tetras, Cardinal Tetras, Black Neon Tetras, and other small characins. They coexist well with Dwarf Gouramis, Kuhli Loaches, and Panda Corydoras, which will occupy the lower level of the aquarium.
Aggressive and large fish are completely unsuitable — cichlids, large barbs, and predators. They will cause constant stress for the Glass Catfish, which may lead to refusal of food and eventually death. Overly active species that would outcompete the catfish for food should also be avoided.
Breeding
Breeding Kryptopterus vitreolus in a home aquarium is a moderately difficult task that rarely succeeds even for experienced aquarists. In the wild, spawning is triggered by seasonal rains and a decrease in water hardness. In the aquarium, you can attempt to replicate these conditions by lowering the temperature by 2-3°C, softening the water, and increasing the volume of water changes.
A separate breeding tank with fine-leaved plants is used for spawning, as the female lays eggs on the foliage. After spawning, the adults must be removed to prevent them from eating the eggs. Fry hatch in 3-4 days and initially feed on infusoria before transitioning to baby brine shrimp. The young grow slowly and require stable water parameters along with frequent small water changes.