Callistus Tetra

Hyphessobrycon callistus, known as the Jewel or Callistus Tetra, hails from the Paraguay and upper Paraná basins of Brazil, Bolivia, and Paraguay. Its body is a striking blood-red with a prominent black dorsal fin, making it one of the most vividly colored small tetras available. The species is closely related to H. eques and H. serpae and has occasionally been confused with them. In optimal conditions with slightly acidic, soft water and a dark substrate, males reach near-fluorescent intensity. It is peaceful in adequate groups but may nip fins of very slow-moving species. A wonderful centerpiece tetra for South American biotope aquariums.

Water: Slightly acidic, soft; pH 5.8–7.5, temperature 22–28 °C. Peat or tannins help achieve best coloration. Tank: 40 L minimum; dense planting, dark gravel or sand, driftwood for cover. Feeding: Omnivore; flake, micro-pellet, live or frozen bloodworm, daphnia, and brine shrimp. Breeding: Egg-scatterer; soft, acidic water and fine plants. Prolific when well conditioned with live foods. Compatibility: Peaceful in groups of 8+; minor fin-nipping possible with very slow or long-finned tankmates.