Stinging Catfish

Heteropneustes fossilis is the sole member of its family Heteropneustidae, a uniquely South Asian air-breathing catfish that possesses long, tube-like air sacs extending from the gill chambers backward into the body cavity. These sacs supplement gill respiration and allow survival in highly deoxygenated water. Its pectoral spines are associated with venom glands, producing a sting that — while not medically serious — is extremely painful and can cause localised swelling for several hours.

In the aquarium, the Stinging Catfish is a surprisingly straightforward species for intermediate keepers. It tolerates a wide range of water conditions, accepts a varied diet, and becomes familiar with its keeper's presence relatively quickly. It is primarily nocturnal and appreciates hiding places by day. The modest adult size of 30 cm makes it manageable in a 300-litre tank — far more practical than most large catfish.

The key hazard is the venom: thick aquarium gloves must be worn during net work or tank maintenance. Never place hands in the tank without protection. With this precaution observed, H. fossilis is a rewarding, curious species with a fascinating biological story to tell.

Water: 22–28°C, pH 6.0–8.0, very tolerant; must have surface air access. Tank: 300 L minimum; secure lid; caves and hiding places; fine substrate. Feeding: Frozen bloodworm and prawns, earthworms, sinking pellets; accepts most foods. Breeding: Nest-spawner; male guards fry; achievable in a large, well-set-up tank. Compatibility: Semi-aggressive; avoid small fish; always use gloves when maintaining tank.