Black Doradid

Oxydoras niger is one of the largest members of the family Doradidae, reaching 120 cm in the wild. Its deep, compressed body is covered in rows of sharp lateral scutes and bears a uniformly dark, almost black colouration. Despite this formidable appearance, it is a strictly peaceful species that feeds primarily on organic detritus, seeds, fruits, and invertebrates — posing no threat to tankmates even when fully grown.

In the aquarium, O. niger is an excellent, if demanding in terms of space, large show fish. Its placid temperament allows it to be housed with fish far smaller than itself without incident. It is primarily nocturnal and most active after lights-out, but becomes bolder in low-light conditions during the day once well-settled. It produces audible croaking sounds through stridulation when disturbed or handled.

Feeding is straightforward — large sinking pellets, earthworms, blanched vegetables, and occasional fruit pieces are all accepted. A fine to medium substrate suits its habit of sifting through the bottom layer. The Black Doradid can live for 20+ years and grows into a truly magnificent long-term companion for the dedicated large-fish keeper.

Water: 22–28°C, pH 6.0–7.5, soft to moderately hard; clean with low nitrates. Tank: 2 000 L minimum; fine sand substrate; large smooth caves; dim lighting. Feeding: Large sinking pellets, earthworms, fruit, blanched courgette; detritivore — varied diet beneficial. Breeding: Not achieved in home aquaria. Compatibility: Highly peaceful; one of the safest large catfish for mixed-species displays.