Arowanas are one of the most sought after predatory fish in the aquarium hobby and are believed to date back over 100 million years. There are six species of true Arowanas, but many of them are restricted by some states. The one most readily available is the Silver Arowana. The Silver Arowana inhabits the Amazon River Basin's shallow, slow moving waters in South America.
If you are planning on getting a Silver Arowana go ahead and plan on a long term relationship. On average, they can live in captivity for up to 10 years, but it's thought that they live much longer in the wild. A true river monster, the Silver Arowana is the largest of all the Arowana species, reaching 3 feet in captivity and getting even larger in the wild.
The biggest challenge you'll face when owning a Silver Arowana is tank size. While juveniles can be kept in smaller aquariums, keep in mind that these fish have a rapid growth rate and can quickly outgrow small tanks. A large tank that can support their growth will allow your Arowana to thrive, with 250 gallons being the minimum. Keeping an Arowana in a small aquarium will lead to stress and possible deformities. This stress will cause your Arowana to become more aggressive and likely to jump out of the aquarium.
Arowanas are top-level swimmers and need a lot of space, so keep decor to a minimum when setting up your aquarium. Some plants around the outer edge of your aquarium and rocks and driftwood that's not too tall will give your Arowana a place to hide when they feel shy while still allowing them to swim freely. Water quality is essential for your Arowana, so you must keep up with regular maintenance and use strong filtration. In the wild, Arowanas will jump out of the water to catch their prey. They are also known to jump out of the water when startled, so one thing you can not go without when housing an Arowana is a lid.
Silver Arowanas are probably the most predatory fish available in the aquarium hobby, so it's no surprise that they are hard to house with other fish. They are very territorial, so you will not be able to keep more than one Arowana together unless you have a huge pond, and even then, you may still have fighting. Silver Arowanas will eat anything that fits in their mouth or that they think will fit in their mouth. There are limited options for tankmates, but if you decide to add another fish, you want to pick larger fish that will not constantly nip at your Arowana. Even when housed with large fish, it is a hit or miss on whether or not your fish will get along, so use caution when adding tankmates. Your aquarium size will also determine if your fish will get along. You'll often see Silver Arowanas kept with fish like Giant Gouramis, Bichirs, Large Plecos, Severums, and silver dollars.
In the wild Silver Arowanas will sit near the surface, waiting for their prey. Other fish, insects, and frogs don't stand a chance from the swift movement and powerful mouth that allows them to hunt from below. Sometimes snakes and birds on low hanging limbs fall victim to the Silver Arowana as they will wait for the right opportunity to jump out of the water and strike. They don't even see it coming. This preditor is omnivores eating the occasional plant based food, but the majority of their diet is meaty foods. In captivity, it is on a case by case basis on what your Arowana will be willing to eat. Most Arowanas start by only accepting feeder fish but can be trained to eat frozen foods like krill and worms and sometimes pellets. With such a fast growth rate, you want to feed your Arowana often and provide a variety.
Owning this river monster is a goal for many aquarium hobbyists but is no simple task. The Silver Arowana requires special care, a huge habitat, and lots of food to allow them to thrive. Their massive size and predatory behavior make them an aquarium hobby icon.