Arowanas are freshwater hard fish of the family Osteoglossidae, otherwise called bonytongues. Right now fish, the head is hard and the stretched body is secured by enormous, overwhelming scales, with a mosaic example of trenches. The dorsal and butt-centric balances have delicate beams and are for quite some time based, while the pectoral and ventral blades are little. The name "bonytongues" is gotten from a toothed bone on the floor of the mouth, the "tongue", furnished with teeth that nibble against teeth on the top of the mouth. The arowana is a facultative air breather and can acquire oxygen from air by sucking it into its swim bladder, which is fixed with vessels like lung tissue.