Osteoglossum is a genus of freshwater fish commonly known as arapaima or bonytongue fish. They are native to the Amazon River basin in South America and are recognized for their unique bony tongues, which help them grasp food. These fish can grow quite large, with some species reaching lengths of up to 10 feet. Osteoglossum species are primarily carnivorous, feeding on smaller fish and invertebrates. They are also known for their ability to breathe air, which allows them to survive in low-oxygen environments. Due to overfishing and habitat loss, some species within this genus are considered vulnerable or endangered.