Parrot-beak Pacu

Ossubtus xinguense is a truly unique serrasalmid that stands apart from all other pacu species by virtue of its extraordinary beak-like jaws, which are unlike the molar-like dentition of most pacu and instead form a sharp, protruding, parrot-like rostrum. Adapted for crushing hard seeds and cracking open tough fruits in the rapids of the Xingu River in Pará, Brazil, it is both scientifically fascinating and visually unlike anything else in the aquarium hobby.

A monotypic genus, Ossubtus xinguense is endemic to the Xingu River drainage and, like many Xingu species, is potentially threatened by the impacts of the Belo Monte hydroelectric complex. It requires the soft, warm, well-oxygenated water typical of the Xingu basin and appreciates strong current and a rocky substrate environment. Minimum tank size is 1200 litres; it should be kept in an unplanted tank with river boulders.

Due to its unique dietary needs — primarily hard seeds, nuts, and tough fruits — it is a challenging species to feed in captivity. High-quality large herbivore pellets, mixed nuts (unsalted), and fresh hard fruits should form the basis of its diet. Ossubtus xinguense is peaceful with other large, non-aggressive species and is the ultimate conversation piece in any specialist South American fish collection.

Water: Soft, pH 5.5–7.0, 24–28°C; well-oxygenated with moderate to strong flow; Xingu biotope conditions. Tank: 1200 L minimum; large smooth river boulders; sand substrate; powerful circulation. Feeding: Hard seeds, unsalted nuts, tough fruits, large herbivore pellets — nut-cracking beak requires hard food. Breeding: Not documented; rare and protected in wild habitat. Compatibility: Peaceful with large non-aggressive SA fish; ideal Xingu biotope companion for large plecos.