Rheoheros coeruleus

Rheoheros coeruleus is a recently described rheophilic cichlid endemic to fast-flowing highland rivers in Chiapas, Mexico. It belongs to a group of stream-specialist cichlids with strongly compressed, robust bodies adapted to life in strong current. Males in full breeding dress develop intense blue-turquoise iridescence that spreads from the head across much of the flanks, creating a spectacular display. The species is seldom available commercially and remains a target species for dedicated Central American cichlid specialists. Aquaria housing this species must incorporate strong flow, high oxygen, and rocky substrates.

Water: 22–28°C, pH 7.0–8.2, hard (GH 12–25); high oxygenation essential. Tank: Minimum 250L with powerheads creating strong directional flow; rocky layout replicating river rapids. Feeding: Omnivore; sinking pellets, live and frozen bloodworm, daphnia, and plant-based supplement. Breeding: Spawns in rock crevices or under flat stones; both parents guard territory aggressively. Compatibility: With other rheophilic species of similar size; avoid soft-water or slow-water species.