It has a long body and a tapered tail and can grow to a maximum size of 90 centimetres (35 in). The juveniles are black with yellow markings down the length of the body, head and the tail. Once it reaches about 15 cm, the markings will disappear and it will start to obtain a dark irridecient steel grey to blue coloration, hence its common name. Additionally, there is a bright yellow and a red outlining or the dorsal, caudal and tail fins
The species is also called water monkey or the monkey fish, because it can literally jump out of the water and capture its prey. It usually swims near the water surface awaiting for potential prey. Although it has been known to eat larger prey like small bats and birds and even small monkeys, their main diets consist of shrimps, insects, smaller fishes and other animals that float on the water surface, on which its draw-bridge-like mouth is exclusively adapted for feeding.
In the aquarium
It is important to have a large enough tank to keep these large fishes. The minimum tank size for one arowana for life is a 96"L x 48"Wx 24"H or 480 gallon aquarium. As it grows, a larger tank will be necessary to insure the maximum length and life span of the arowana. The tank must have a sturdy lid, as these fish are active jumpers and will jump out of the tank to their demise.
Water conditions are important for arowanas. Some black water additives can help simulate the arowana’s natural habit.
- Black arowanas can adapt to most water supply and thrive
- Temperature - 24°C to 28°C, but best at 26°C
Also a 25-30% water change is necessary 1-2 times every week to maintain excellent water conditions.
Although not tested scientifically, there might be an association between overfeeding and development of drop eye, and therefore it is important that young arowana are not overfed. Arowanas will eat insects, shrimp, pellets, live fish, beef heart, frogs, etc. The best diet for arowanas is pellets, live crickets, and shrimps. Small feeder fish are often raised in poor conditions and can carry many diseases transmittable to predatory fishes.
Any fish will do as long as it does not fit in the arowana’s mouth. Many people like having more than one arowana in the tank. That is not a problem, but there must be at least 5-6 individuals per tank because arowanas are very aggressive towards each other.
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