外齒油鯰

The <em>Exallodontus aguanai</em> is a freshwater fish belonging to the family Pimelodidae, the long-whiskered catfishes — a diverse family of South American catfishes typically characterised by elongated barbels and robust, scaleless bodies. Adults of this species reach a maximum recorded length of approximately 20 cm, and it has been documented at depths ranging from 20 to 30 metres in riverine environments, suggesting an association with deeper river channels rather than shallow marginal habitats. Pimelodids are distributed across major South American river drainages, including the Amazon, Orinoco, and Paraná basins. Members of this family are predominantly nocturnal predators, using their well-developed barbels to detect prey and navigate in turbid, low-visibility freshwater environments. <em>Exallodontus aguanai</em> may be associated with large river systems in the central Amazon region, though detailed distribution records are not comprehensively established. Details of habitat and range for this species remain limited in the ichthyological literature. Like many pimelodids, this species is likely carnivorous, feeding on smaller fishes, invertebrates, and carrion near the river bottom. The name <em>aguanai</em> may reflect a vernacular or indigenous name from the region of collection, a common practice in the taxonomy of Amazonian fishes.