Glass Catfish

1 Glass Catfish Introduction

The Glass Catfish has a fully transparent body, and the two whiskers at its mouth resemble a cat’s whiskers, giving it its name. It swims very fast; when stationary it holds a 40-degree upward tilt. Occasionally, under the right angle of light, it shows dreamy rainbow colors.

Chinese name: Glass Catfish

Kingdom: Animalia

Class: Pisces

English name: Glass Catfish

Named: 1839

Care difficulty: Easy

pH: 6.3-7.0

Binomial: Kryptopterus bicirrhis

Phylum: Chordata

Distribution: Thailand, Malaysia, and Indonesia in Asia

Named by: Valenciennes

Diet: Prefers live foods

Hardness: 3-6 dGH

Water temperature: 20-25°C

2 Physical Characteristics

The Glass Catfish has a very distinctive appearance: a fully transparent body with two cat-like barbels at the mouth. It is hard to spot unless observed carefully. Because you can see a fish skeleton drifting in the water, it is also called the ‘Ghost Fish’.

Adult Glass Catfish reach 12-18 cm. The name comes from the transparent body and the two long cat-like barbels. They swim swiftly and, when stationary, hold a 40-degree upward tilt, their crystal-clear bodies swaying slightly; occasionally, under the right light angle, they show dreamy rainbow colors like those of refracted sunlight through a prism.

They reach 10-12 cm and look like a willow leaf. The snout is pointed with two long barbels that often extend forward or rotate freely, sensing current, threats, obstacles, and helping find food. The chest and belly are very short, making up only a quarter of the length. The caudal peduncle is very short with a forked tail. The dorsal fin is reduced; the anal fin base is long with equal-width rays. The whole body is transparent, with the spine, fin rays, and internal organs clearly visible. The color is pale jade-green, like a fine jade carving.

3 Aquarium Conditions

The Glass Catfish is peaceful and likes to be kept with its own kind; a lone individual becomes lonely and may die. It can also be mixed with gentle, slow small fish. The water needs some hardness but not above 10°dH; suitable temperature is 22-26°C.

In fact, keeping the Glass Catfish only requires keeping nitrite low. It is gentle but timid and dislikes swimming, often hiding in dark corners, so plant plenty of aquatic plants for shelter. It is sensitive to temperature changes; below about 18°C its transparent body gradually turns white, and if the temperature keeps dropping it curls up, stiffens, and dies.

4 Feeding Guidelines

The Glass Catfish is easy to keep and feed; it eats common live foods such as tubifex, daphnia, and brine shrimp. In the wild it can reach 8 cm.

Newly hatched fry are pale yellow; under a dissecting microscope you can see the beating heart and flowing blood, with a large unabsorbed yolk sac on the belly. For the first 2-3 days the fry lie on the bottom and need no feeding. Promptly remove egg membranes and white dead eggs, change water daily, and keep fry at 25°C (e.g., in an air-conditioned room). At 3-4 days they swim freely and start feeding; stir a little egg yolk in water until faintly yellow. Add calcium tablets, vitamin B complex, and terramycin to improve survival. Feed small amounts often, 3-4 times daily. At 7-10 days add paramecium and brewer’s yeast; at 3 weeks feed brine shrimp nauplii and gradually add prepared food. Watch water quality, change water often, and feed little and often for healthy growth.