Ageneiosus Ucayalensis

Datasheet

General Description

The Ageneiosus Ucayalensis, commonly known as the Ucayali Dolphin Catfish, is a polymorphic species with body patterning varying significantly based on locality. It is classified under the order Siluriformes and belongs to the family Auchenipteridae. This species showcases unique characteristics such as elongated and laterally compressed body, deeply forked caudal fin, and very long anal fin with 41-50 rays.

Aquarium Setup

For optimal care, the Ucayali Dolphin Catfish should be housed in a tank with a minimum size of 600 liters. The tank setup should include dim lighting and refuges like driftwood, large rocks, or plastic piping. A robust filtration system, regular water changes, and maintenance of high dissolved oxygen levels are crucial. Water conditions require a hardness of 18-357ppm, a pH range of 5.5-7.5, and a temperature between 22.5-28°C.

Behaviour

Known for consuming large prey items, this species is best kept with similarly-sized catfish or pelagic characins like Brycon, Colossoma, or Piaractus, though such combinations are typically observed in public aquariums due to compatibility issues in home setups. The Ucayali Dolphin Catfish is a predator that feeds on invertebrates and other fishes, showing a preference for live prey initially but can be transitioned to thawed frozen foods or pellets meant for carnivorous species.

Feeding and Diet

The diet of the Ucayali Dolphin Catfish consists primarily of invertebrates and other fishes, with a capability to consume surprisingly large prey. While newly-imported specimens may resist non-live foods initially, most individuals can be weaned onto thawed frozen whitebait, shellfish, or pellets. Feeding mammalian or avian meat is discouraged, as well as relying solely on feeder fish due to parasite and disease risks.

Reproduction & Dimorphism

Reproduction of the Ucayali Dolphin Catfish in aquariums remains unrecorded, but observed courtship behavior in closely related species involves internal fertilization. Adult males exhibit seasonal sexual modifications, with ossified and extended maxillary barbels and dorsal fin rays used for courting females. Males also display enlarged anal fin rays serving as support for the intromittent organ. In contrast, females have longer anal-fin rays compared to males.

Habitat and Distribution

This species, initially described from the Río Ucayali in Peru, has a broad distribution across Ecuador, Colombia, Peru, Brazil, Venezuela, Guyana, Suriname, and various river basins. Typically found in middle to lower sections of river channels and larger tributaries, the Ucayali Dolphin Catfish thrives in diverse habitats, showcasing a generalist preference due to its extensive natural range.