Hump-backed Headstander Tetra

Charax gibbosus is a distinctive mid-water characin from the Amazon and Orinoco basins with a deeply arched, hump-backed dorsal profile that gives it an almost comical appearance from the side. It is a predatory species equipped with strong, sharp teeth and a protruding lower jaw, preying on small fish and invertebrates in the wild. Despite its predatory nature it is a less extreme piscivore than cynodontid relatives and can coexist with medium-to-large fish it cannot easily overpower.

In the aquarium Charax gibbosus is kept in a minimum 200-litre setup with soft to moderately hard water, good filtration, and adequate hiding spots. It is a somewhat secretive species that appreciates driftwood and overhanging cover. It will target smaller fish but is more manageable than the larger predatory characins and can be an interesting component of a specialist medium-large South American display.

Feeding includes frozen bloodworm, small frozen fish, shrimp, and gradual weaning to carnivore pellets. Its unique humpbacked profile makes it visually distinctive and it is a popular if little-known species among collectors of unusual SA characins. The translucent quality of its flanks reveals internal organs under good lighting, adding to its fascination.

Water: Soft to moderately hard, pH 5.5–7.5, 24–28°C; good filtration; moderate flow. Tank: 200 L minimum; driftwood cover; open mid-water for hunting. Feeding: Semi-predatory — frozen bloodworm, shrimp, small frozen fish; wean to carnivore pellets. Breeding: Not documented. Compatibility: Semi-aggressive toward small fish; compatible with medium-large SA species.