Phractocephalus hemioliopterus, commonly known as the redtail catfish, is a large freshwater fish native to the Amazon, Orinoco, and Essequibo river basins in South America. It has a striking appearance with a vibrant red tail, a broad, flat head, and long whisker-like barbels. This species is known for its opportunistic feeding behavior, preying on fish, crustaceans, and detritus. It plays a critical role in the ecosystem as a top predator, helping maintain the balance of aquatic life.

Phractocephalus hemioliopterus, commonly known as the redtail catfish, is native to the Amazon, Orinoco, and Essequibo River basins in South America. This includes countries such as Brazil, Venezuela, Colombia, Peru, and Guyana.

The redtail catfish typically inhabits freshwater environments such as large rivers, floodplains, and lakes. These areas are characterized by warm tropical climates with water temperatures ranging from 22°C to 26°C (72°F to 79°F). The water bodies are often turbid with soft, muddy substrates.

As a benthic predator, the redtail catfish occupies a niche where it feeds on a variety of prey including smaller fish, crustaceans, and invertebrates. It is adapted to a nocturnal lifestyle, often hunting at night in the murky waters of its habitat. The species plays a significant role in its ecosystem as both a predator and a scavenger, contributing to the balance of the aquatic food web.