Brachyplatystoma is a genus of catfish from the family Pimelodidae. As the occasionally used common name goliath catfishes indicates, this genus includes some of the largest species of catfish, including the Piraíba, B. filamentosum, which reaches about 3.6 metres (12 ft) in length. Brachyplatystoma are found in the Amazon and Orinoco Rivers, and other tropical freshwater and brackish habitats in South America. Some species are migratory. These fish are important as food fish and, to some extent, aquarium fish. Fish of this genus are found in the Amazon, Orinoco, and The Guyanas in South America.The genus does not occur west or north of the Andes or in the Venezuelan Coastal Range. These fish generally inhabit areas that have a soft substrate, such as mud or sand.