Osteoglossidae – Bonytongues

Their name derives from their unique anatomical feature—a bony, toothed tongue that fits into a similarly toothed groove in the roof of the mouth, aiding in their specialized feeding habits. Members of the Osteoglossidae family are characterized by their elongated bodies, large scales, and the distinct jaw morphology that gives them their name. These fish are predominantly large, with some species growing to substantial sizes, making them among the largest freshwater fish in their respective regions.

Osteoglossidae species are distributed in tropical freshwater systems across the world. The Asian Arowanas inhabit slow-moving rivers and basins in Southeast Asia, while the Silver and Black Arowanas are found in the Amazon River. The Australian Arowanas are native to northern Australia, thriving in rivers and billabongs. They are generally carnivorous, feeding on a diet that includes fish, insects, and even small birds and mammals. Some species have been observed leaping from the water to catch low-flying or perched prey. This impressive predatory behavior is coupled with some species exhibiting advanced parental care, such as mouthbrooding by males, who protect the eggs in their mouths until they hatch and the fry is relatively mature.

These fishes are deeply embedded in the cultural fabric of the regions they inhabit. Particularly in Asia, the Asian Arowana is considered a symbol of luck and prosperity, often kept in aquariums where they are believed to bring good fortune to their owners. This cultural value can drive the prices of these fish to high amounts, making them among the most expensive aquarium fish in the world.