It is an ancient freshwater fish. The body length is about 1 metre and its weight is more than 7 kilograms. The body side is flat. The belly side is also flat that make sharp ankle. Its scales are large and thick. It has 21 – 24 lateral line scales. Dorsal fin and anal fin locate far back on the body. It has elongated pectoral fin which is about one-third of its body length. Its caudal is round edge in shape. The mouth is oblique with a very wide gape and slant upward. The lower jaw has 1 pair of big and short barbel at its tip.
The breeding zone of asian arowana starts from Thailand to Malaysia and Indonesia. It is found in slow stream community in the area of Rayong, Chanthaburi, and Trat Province. Also, it is found generally in many rivers in the area of Surat Thani and Satun Province. Most of them are muddy streams that contain less acid and water ground is a mix of stone and sand.
It eats small fishes, frog, young shrimp and other aqua animals, including small land animals that fall down the river.
It is aggressive and possessive toward its habitat. It likes to bite and harm other fishes even same species fishes, then it should not be raised together with other fishes.It has a unique type of mating as it spawns a few eggs in each time. The female who weights 3 – 6 kilograms spawns only 40 -100 eggs. Each egg has an average diameter at 1.72 centimeters. After spawning, it will incubate by swallowing the eggs until they are hatched out. The parents protect baby whenever the danger comes. The parents will open their mouth so that the baby can get inside and hide the enemy.
It is a protected animal of Thailand under Thai Wildlife Protection Act B.E. 2535