Cyclostoma Pike Cichlid

Crenicichla cyclostoma is a fascinating rheophilic (current-adapted) pike cichlid from the rapids zones of the Rio Tocantins in Pará state, Brazil. Named for its rounded, somewhat circular mouth — an unusual feature among pike cichlids — this species has evolved a slightly more compressed body and stronger pectoral muscles than typical Crenicichla to cope with the energetic flow of Tocantins rapids.

In the aquarium, C. cyclostoma benefits from strong filtration and water movement that replicates its natural rapids habitat. The tank should feature smooth, rounded boulders and flat stones mimicking the rocky substrate of its native environment, along with fine sand in sheltered areas. High oxygen levels are important and can be maintained with a spray bar return or powerhead.

Feeding is adapted to the current-dweller lifestyle: this species is an efficient stalker in flowing water, targeting small fish, invertebrates, and aquatic insects. In captivity, frozen carnivore foods are accepted. The species is somewhat more demanding than most pike cichlids and is best suited to experienced Crenicichla keepers.

Water: Soft, acidic (pH 5.5–7.0) at 24–28°C; high water movement and oxygenation essential. Tank: 180 L with smooth boulders, flat rocks, and a powerhead or spray bar for flow. Feeding: Frozen carnivore foods; live prey appreciated to stimulate natural hunting behaviour. Breeding: Cave spawner in rocky crevices; high flow and oxygenation should be maintained during spawning. Compatibility: Species tank; few fish can tolerate the current levels this species prefers.