Red rainbowfish

The red rainbowfish (Glossolepis incisus), also known as the salmon-red or New Guinea rainbowfish, is a strikingly coloured freshwater species endemic to Lake Sentani and its tributaries near Jayapura in Papua, Indonesia. Males develop a brilliant red body and a distinctive high-backed profile as they mature, while females and subordinate males remain olive-brown. Reaching up to 15 cm (6 in) in the wild, though typically 12 cm in aquaria, these active midwater swimmers bring vibrant movement to any community tank. The species is classified as Endangered in its native range due to habitat pressure from human population growth and introduced species such as tilapia, though it is readily bred in captivity and widely available in the trade.

Red rainbowfish are very peaceful by nature but their rapid movements and active swimming can disturb smaller or slow-moving tankmates, so they are best housed with similarly sized rainbowfish, characins, danios, barbs, or Corydoras catfish. They are strongly schooling and should be kept in groups of at least six to eight, which encourages males to display their best colouration. A minimum tank of 110 L (29 gal) with a length of at least 120 cm is recommended to accommodate their active swimming, furnished with dense planting along the sides and open swimming corridors in the centre. Water movement should be gentle.

Water parameters should be maintained at 22-25C (72-77F), pH 7.0-8.0, with moderate to hard water (10-20 dH); they will not thrive in soft, acidic conditions. They accept most dried, frozen, and live foods readily, with regular feedings of live or frozen options enhancing colouration. Breeding is straightforward: the pair scatter eggs among fine-leaved plants or spawning mops over several weeks, and the eggs hatch in 7-8 days. With proper care this species can live 6-8 years in the aquarium.