Silver Arowana - Osteoglossum bicirrhosum The Silver Arowana comes from the Amazon River in South America. The silver arowana is a very beautiful and a fascinating fish to watch. However, because of their huge adult size of 35 - 40 inches (89 - 102 cm) they are not recommended for the beginning aquarist. Actually, this is one of those fish that are probably best kept in the wild or in huge public aquariums. The Silver Arowana requires at least a 200 gallon (750 liters) tank to adequately keep them. You also need an excellent aquarium filter such as an external canister filter. Arowanas are also excellent jumpers so you will need a good, tight fitting hood with no escape holes. In the wild, the Silver Arowana can jump out of the water at insects and small animals on overhanging branches. Because of their potential adult size, there are not many compatible tank mates that quickly come to mind but you may be able to keep an Arowana with a larger Common Pleco. Th