Arowanas, also known as aruanas or arawanas are freshwater bony fish of the family Osteoglossidae, sometimes known as "bony tongues." In this family of fishes, the head is bony and the elongate body is covered by large, heavy scales, with a mosaic pattern of canals. The dorsal and the anal fins have soft rays and are long based, while the pectoral and ventral fins are small. The name 'bony tongues' is derived from a toothed bone on the floor of the mouth, the 'tongue', equipped with teeth that bite against teeth on the roof of the mouth. The fish can obtain oxygen from air by sucking it into the swim bladder, which is lined with capillaries like lung tissue. The arapaima is an "obligatory air breather".
Asian arowana refers to several varieties of freshwater fish in the genus Scleropages. Some sources differentiate these varieties into multiple species,while others consider the different strains to belong to a single species, Scleropages formosus.They have several other common names, including Asian bonytongue, dragon fish, and a number of names specific to different varieties.
Native to Southeast Asia, Asian arowanas inhabit blackwater rivers, slow-moving waters flowing through forested swamps and wetlands. Adults feed on other fish and shrimps, while juveniles feed on insects.
These popular aquarium fish have special cultural significance in areas influenced by Chinese culture. The name dragon fish stems from their resemblance to the Chinese dragon. This popularity has had positive effects on their status from being extinct. Arowanas are also used for feng shui to bring good luck and wealth.
Arowanas tend to merge in groups of 5 to 8; any fewer may show an excess of dominance and aggression. Keep this fish in a minimum of about 750 litres (240 gallons)for a single fish with good filtration, add another 100 for every other fish kept. This fish should not be purchased by an amateur fish hobbyist. Some compatible fish to partner with this fish are clown knifefish, pacu, oscars, plecostomus, jaguar cichlids, green terrors, gar and any other semi-aggressive fish that cannot fit in the arowana's mouth.