The Arowana (Osteoglossum bicirrhosum) is a long, sleek and extremely streamlined fish of great beauty. They're silver in colour and their large scales have a bright reflective sheen. There are two barbels attached to the lower lip (used for smell) of the cavernous mouth which opens like a trap door. Thus, it is capable of swallowing a very large meal. It is not everyone's taste and neither can it be housed in a standard sized aquarium.
An unusual aquarium oddball with a unique character which can become an aquarists pride and joy. These fishes have the potential for rapid growth and in most cases do grow very quickly especially when fed a high protein diet. They can reach up to 120 cm in length which is large by aquarium standards. So when considering purchasing one of these giants be prepared to house it in large quarters. An aquarium of 6ft×2ft×2ft is a good size for this fish, but be prepared to move it to larger quarters as the fish reaches the 2 to 3ft. mark.
These fishes are surface dwellers and will glide just below the water surface keeping a sharp eye out for low flying insects to catch by surprise. In nature they can be found in still waters of lakes and rivers. Arowanas are excellent jumpers and therefore should be covered in aquarium conditions to prevent a prized specimen from leaping out of its tank. Juveniles are also capable of jumping great distances. These fish can be a bit jittery when first introduced to their new home, so a sturdy cover is essential.
Feeding an Arowana is not usually a problem. Be aware however that they are surface feeders and generally will not take food from the bottom. They prefer to take food high up in the water column. They are not fussy feeders, taking all meaty based foods such as: raw beef heart, raw fish, prawns. They will also take dried pellet foods. Earthworms are a favourite and are accepted with gusto. They attack their food during feeding time as they coil their bodies like a spring and lunge forward to engulf the tasty morsel. Feeding this fish provides great entertainment for its owner - it really is a fun fish. If you need a good supply of earthworms and are not keen on getting your hands dirty digging in the garden - use some potassium permanganate. Dissolve the crystals in a bucket of water until the water turns medium purple in colour. Pour the water onto an area where you think the worms have burrowed and wait a short while. Within a couple of minutes, if there are any worms, they will be popping up out of the ground.
Arowanas are not prone to disease and are quite hardy when acclimatised. It is the authors experience that they can be a bit sensitive to water change especially when being introduced to a newly set up aquarium filled with freshwater. The water must be allowed to mature to ensure the safe introduction of this fish to its new home. Therefore acclimatise slowly by adding small quantities of aquarium water to the bag containing the new fish over a period of 30 minutes to an hour. pH 6.8 slightly acidic will suit this fish. The water may also be filtered through peat.
Housing these fish on their own is probably the best option, but if you really must have other tank mates choose those that are large and placid in nature. Large Tinfoil Barbs, big Hypostomus, Oscars and other large non aggressive species. Be aware that Arowanas tend to bite each other when kept in quarters that are not of adequate size. This can still occur in very large aquaria, so be prepared to separate them if necessary.
Due to the great size that this fish reaches, it is unlikely that it can be spawned under aquarium conditions unless the breeding quarters are very large. Female Arowanas incubate the eggs in their mouths and release the free swimming young after approximately two months.
If you have a large enough aquarium to house this oddball you will enjoy owning such a beautiful and graceful fish as it cruises the length of the tank waiting to be fed its dinner. Hopefully, it won't be you!
