Ain't An Arowana?

There is a fish called an Arowana; if you've been around freshwater aquariums for a little while you've likely seen one in your LFS; they are large scaled, long, slender animals with a graceful swimming style. This list of attributes has made them iconic in aquariums and revered as holy in some places. Some cultures hold them in high reverence, and they are a symbol of wealth and good luck in much of China. That fish is another story for another day.

There are another fish shares this name, and while also amazing in a myriad of ways, it isn't actually an Arowana; Heterotis niloticus is this fish. Most commonly called the African Arowana, it is also frequently, and accurately called the African Bonytongue. It is closely related to another legendary fish, the Arapima. Both of these fish have a very hard tongue and palate, and are interestingly both obligate air breathers, they need access to the surface of the water so they can gulp down large mouthfuls of air in order to breathe. Also, like the Arapima, though not quite on the same scale, Heterotis niloticus is truly a monster fish in the making.

The African Arowana is (also) a long, slender and graceful fish. Though unlike their namesake, they are more revered as a food fish than for any type of symbolism. In good conditions, they grow quickly, getting over 20 inches long and weighing more than seven pounds in the first year, making them an excellent candidate for growing out as food. In addition, they are very high in Omega-3 fatty acids. Throughout much of Africa, these fish are eaten fresh (frequently fried) and often dried to use in broth and seasoning, not unlike bonito flakes in Japan. They are incredibly successful in the right environments, but were traditionally difficult to aquaculture, though recent developments from research in commercial, food-based aquaculture have made them much more easily available.

In the wild, these fish were originally found in the Niger River, but have been introduced into many rivers and impoundments around Africa both intentionally and as a result of rearing ponds overflowing. They live in slower water areas of rivers, as well as lakes and ponds that have abundant vegetation. They make very distinctive nests that are akin to a miniature beaver dam that is shaped like a four-foot-wide doughnut that pokes out of the surface. When the fish are hatched, they live in this enclosure for five or so days until the parents break them out, and the male will continue to defend them for some time. After parenting, the juveniles will remain in these shallow waters, but the adults will disperse into deeper water.

The Niger River they originate from is a warm body of water, and these fish will continue to need this condition in the home aquarium, shoot for temperatures between 75- and 85-degrees Fahrenheit. They'll do best in a moderate pH, and are naturally found in areas that can be as different as 6.5 and 8.0 African Arowanas don't seem to care much about the hardness levels of the water they are kept in.

There used to be some debate as to what the African Arowana ate, and this is because it eats pretty much everything. Stomach assays of wild fish include invertebrates like freshwater shrimp, copepods (lots of copepods) small snails and bivalves (clams,) but they also include some fish, phytoplankton, plant matter, and even mud! There is some debate about whether or not the plant matter and mud are byproducts of eating the inverts, but it could still be an important element of their diet. Some keepers of them say they can and will eat grain! Here we feed them a meaty mix of foods like Gamma Bloodworms, Mysis, Krill, Chopped Mussel and Chopped Prawn, and we're introducing them to Nutramar Algae and Color Boost Shots. Getting them onto a high-quality pellet is not that challenging and is important. They have a relatively small mouth for such a large fish, and Nutramar Pellets offer a great way to get them nutrient dense meals, while maintaining balanced nutrition. These fish need to be fed frequently when small, a minimum of three times a day and some commercial rearing operations feed them every three hours. This is likely overkill, but the quicker they can get on a pellet, the easier it is to utilize automated feeders to satisfy some of their nutritional needs.

This is a fast-growing fish that can achieve a preposterous max size of nearly four feet long (the world record), though they reach maturity around 15 inches long or so. The elephant in the room, is well, the elephant. These fish get big and will need a massive display or pond within a relatively short period of time; one measured in the hundreds of gallons. Any invertebrate that they can fit in their mouths, and catch, will be seen as food, though they can be kept with other large fish. The only catch their appetite, as we referenced earlier, African Arowanas eat a lot, and other fish might get out-competed for food. As juveniles (less than eight to ten inches or so) they can be kept in groups but will become territorial with each other once they reach adulthood, and this can end in fatalities.

Are you the aquarist who is endlessly intrigued by oddball and monster fish? Do you have a truly massive aquarium or tropical pond waiting for possibly the coolest addition it has ever seen? Are you looking to grow out some highly sought after and delicious food fish? If you can check any two of these boxes, Heterotis niloticus might be just the fish you've been dreaming of. Head to your LFS and ask them about getting you an African Arowana from Aquatropic today!