Silver Arowana 10 – 12cm

The Silver Arowana, also known as the Dragon Fish or Monkey Fish, is a freshwater fish indigenous to South America.  Renowned for its hunting ability and large size, this fish is one of the most iconic around and will be the prized possession of any hobby aquarist. Whilst not generally recommended for beginners, this fish can make a fantastic addition to an experienced keeper’s tank.

The Silver Arowana is not a fish that is suitable for beginners. Due to its large size and long life expectancy, only more experienced aquarists should undertake this challenge. It requires an enormous tank (at least 950 litres in capacity) and finding suitable tank mates for them can be challenging.  They are considered to be carnivores and eat large quantities of food.

Behaviour

Arowana are strong powerful swimmers, and can be fairly aggressive at times. They are a predator fish that can grow up to a meter in size and weigh in excess of 6kg. If you ever encounter them in the wild, you will notice their unique hunting style. They have a huge leap which allows them to hunt animals on low level branches etc. They also have the ability to survive short periods of time out of water, by using their swim bladder.

Tank Conditions

For a large fish they can be surprisingly skittish. Arowanas will get scared from sudden movements, for example when you approach the aquarium quickly, or turn the lights on.  You should make sure to keep your Arowanas in a tank placed in a low foot-traffic area. This prevents them getting startled each time you walk past the aquarium. When watching your Dragon Fish, you will notice they spend most of their time swimming close to the surface of the water.

However it should be noted that Silver Arowanas are notorious jumpers. It’s been claimed that they can jump up to 3 meters high. They are most likely to jump when they are new to an aquarium or are placed in an aquarium which is too small for them. When placed in an aquarium that is too small for them, they will repeatedly try to jump to freedom. Even if the aquarium is covered, they will still jump and can injure themselves when bouncing off the lid. Finally you will need a very heavy cover to stop them jumping out of the tank.

Juveniles can be raised in a smaller tank of 240 litres, but will quickly need moving out into a larger aquarium.  If they aren’t moved into a large enough tank, you will quickly start to have problems with your Arowana, most notably body deformation and reduced lifespan.

The substrate should consist of fine, small gravel. The tank should be sparingly planted, and have lots of open space for them to move around in. If you like to decorate your aquarium, you can do so with driftwood, rockwork and sturdy plants. You should avoid plants with weak roots as they can be dislodged by Silver Arowanas.

Compatibility

The first thing to remember about Silver Arowanas is that they are first and foremost a predator fish. This has implications for their compatibility and which fish can share a tank with them.

Juveniles

When they are young they are particularly susceptible to bullying by more aggressive breeds. So you should bear this in mind when placing them in an aquarium. You should also know that when young, they can be kept together and raised. It’s recommended that you keep 6 or more Silver Arowanas together. This prevents the smaller ones from being excessively bullied by the larger Arowanas.

Adults

It probably isn’t surprising to hear that finding ideal tank mates can be difficult. This is because they are targeted by aggressive fish due to their size. On the other end of the scale, smaller fish aren’t good tank mates as they usually end up being eaten by Silver Arowanas; remember they are a predator fish. However, there are still lots of species which can live with Arowanas. When assessing fish to keep with your Arowana, keep in mind these three general rules:

1. You want to find peaceful yet slightly aggressive fish.
2. Fish should also be large enough that they can’t be eaten by the Arowana.
3. You should introduce the Arowana to the tank first.

So good examples of this would be: Green Terrors, Oscars, Knifefish, Large Plecostomus, Parrot Cichlid, Angelfish and Catfish. Remember though that temperaments of individual fish can vary hugely, so always have a backup plan if they don’t get along.

If you plan on keeping multiple adult Arowanas together, do so cautiously. They generally don’t get along well together. If you are insistent, you should keep at least 6 of them together and keep them in a large natural pond (or an aquarium of similar size).

Feeding

Silver Arowanas are generally considered to be carnivores, however they are occasional omnivores. In the wild they will consume a wide variety of prey including: small fish, snails, large insects, rabbits, frogs and even snakes! However, if given an option, their food of choice is normally small fish and crustaceans.

Arowanas have a distinctive hunting style. Due to the position of their mouth they can swim just below the water line before jumping up out of the water to catch their prey. They can also catch small fish by swimming beneath them and scooping them up.

When keeping these fish you want to make sure their diet is as close to what they would eat in the wild, such as fish foods for carnivores. Their preference is a meat-based diet, which can include: earthworms, crab, crickets, shrimp, beef heart, krill and crustaceans.

You can also give them feeder fish. This allows you to watch them hunt which can be very absorbing. If you want to use feeder fish, I would generally recommend you breed your own, this way you can ensure the breeder fish are healthy.

Finally, it should be noted that juvenile Arowanas are very fussy eaters.

Care

Arowanas tend to display a more vivid coloration if the water is a bit more acidic. As Silver Arowanas are particularly susceptible to poor water quality, strong water filtration is required, in addition to weekly water changes of 25%. Like other freshwater fish, Silver Arowanas are tolerant to changes in these conditions; however you should aim to keep your water within the tolerances outlined below.

See Fish Disease Diagnosis and Treatment at Rebel Pets for help with diagnosing and treating diseases.