Like all aquarium fish, the Arowanas natural habitat dictates how best to care for them in captivity. Although Arowanas have been kept in captivity for decades, this is just a drop in the bucket in terms of their existence in the wild.
Arowanas are considered “living fossils” and their presence has been established for 60 million years or more. Its ancestral history goes back more than 130 million years. The longevity and freshwater evolution of the 7 Arowana species point to their successful adaptation to their environment.
As much as possible, the natural habitat of Arowanas should be mimicked for their success in captivity. As closed systems, it is of course impossible to leave Arowana care to “natural” processes in the aquarium. But it is possible to let their natural preferences guide how we care for them to best support their health and promote well-being.
From nature to nurture
Most Arowana fans know that the Asian varieties are native to the blackwater river areas of Southeast Asia. The four varieties of Asian Arowana each originated from different freshwater areas of Malaysia, Thailand, and Indonesia. The unique physical characteristics of these rivers, swamps, and wetland areas dictate optimal tank conditions for captive Arowanas.
water attributes
i) Temperature: Arowana’s native habitats are located very close to the equator in tropical areas. Therefore, the water temperature should be maintained at approximately 80°F (27°C). The water temperature would vary little in the Arowana’s natural environment, and they also do not tolerate fluctuations in aquarium temperatures.
ii) Blackwater: Arowanas natively inhabit blackwater rivers and wetland areas. Blackwater is incredibly clean and tends to support a wide variety of unique fish species specially adapted to its attributes. Blackwater is soft, acidic water fed by blackwater streams originating from old-growth tropical forest soils that are low in nutrients. The lack of minerals present in these soils keeps the sewage soft. Decaying leaves from Ketapang trees that fall into the black water release tannins and humic acids that soften it further. These organic acids stain the water a distinctive tea color.
The brownish-yellow color of blackwater is thought to contribute to the bright, iridescent colors typical of many blackwater fish species, including arowanas. Vibrant coloration can make it easier for species to see each other in dark-colored water.
With this in mind, many hobbyists try to reproduce blackwater conditions in their Arowana aquariums. Ketapang dried leaves are used to promote a healthy environment and lower the pH of tank water. The natural organic acids released by the leaves can help absorb undesirable chemicals, detoxify the tank, and reduce the population of undesirable bacteria.
Peat and decayed driftwood are two other blackwater additives used in Arowana tanks. Commercially prepared “black water extract” is another option. When creating black water conditions, care must be taken that the pH of the tank does not become too acidic or drop below 6.5 – 7.0.
Feeding
i) Diet: Arowanas in the wild are surface-feeding predatory fish, hunting in shallow, shady areas along the shoreline. They are known to jump after food by flying or hanging above the surface. Their diet consists of live food in their natural environment, and it is what they prefer to be fed in captivity.
Not only is it possible, but it is also advisable to tune your Arowana to eat some non-living foods. But to mimic their natural environment, nothing comes closer than live foods. In the wild, arowanas have been known to feed on insects, spiders, frogs, fish, lizards, birds, bats, and even small monkeys. In captivity, farm-raised shrimp, worms and feeder fish allow arowanas to exercise their natural hunting instincts.
Their natural diet also makes it difficult to find suitable tank mates for an Arowana. In the wild, they commonly consume anything small enough to fit in their mouths. The same tends to happen in captivity.
ii) Feeding schedule: Many experts doubt that Arowanas feed every day in their natural environments. Even a large tank allows only minimal exercise for Arowanas kept in captivity. Therefore, daily feeding is unnecessary and may compromise water quality.
iii) Tank Cover: Another direct result of their natural feeding habits is the Arowana’s tendency to jump out of their tank. Great care must be taken to secure the aquarium lids. Trying to discourage jumping in any other way is unlikely to be fruitful and may harm the fish.
Clothing
Arowanas are usually found singly or in small groups in the wild. They are extremely territorial and aggressively defend the areas they occupy. His natural instincts are at odds with housing Arowanas together.
Other aggressive or surface-swimming fish are likely to appear threatening to an Arowana. Reduce the risk of altercations by choosing one or two shy, bottom-dwelling or larger tankmates to house Arowanas.
environmental elements
Although Arowanas are typically found in shallow water filled with reeds, wood, rocks, and aquatic plants, most hobbyists prefer to keep Arowana tanks sparsely decorated. This helps prevent injury to the fish and makes tank maintenance less tedious. Artificial plants and decorations that do not interfere with surface swimming habits are safe, low-maintenance alternatives to providing some “natural” habitat features.