Uaru amphiacanthoides is native to the middle Amazon River and its major tributaries in Brazil and Peru, where it inhabits slow-moving rivers, floodplain lakes, and flooded forests with very warm, soft, blackwater conditions. It is closely associated with the same habitat as Discus and shares similar water quality requirements.
The Uaru has an unusual, triangular body profile that makes it instantly recognizable. Adults display a warm golden-brown to copper body with a large black triangular blotch on the flanks and traces of iridescent markings. Juveniles have a more spotted appearance that changes dramatically as the fish matures. Adults reach 25 cm and are impressive, deep-bodied fish.
The Uaru is a dedicated herbivore, consuming plant material, algae, and soft aquatic vegetation in the wild. In the aquarium, it will systematically consume most live plants and must be fed a heavily plant-based diet of spirulina, blanched vegetables, and herbivore-specific foods. Failure to provide adequate plant material in the diet leads to digestive issues.
Despite being peaceful, the Uaru is classified as advanced due to its demanding water quality and dietary requirements. It needs very warm water (26–30°C), very soft and acidic conditions (pH 5.0–7.0), and a pristine, high-quality environment. Nitrate sensitivity is high; excellent filtration and frequent water changes are non-negotiable.
