Silver Arowana (Osteoglossum bicirrhosum) care sheet

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The Silver Arowana is possibly one of the coolest freshwater fish in your aquarium and a staple for large tank systems. These monster fish can easily grow to be over two feet in length, are up to 20 years old, and have a huge mouth that can easily suck in smaller fish and invertebrates. Although silver arowanas are typically sold as hatchlings, understanding the true size, lifespan, and nutritional needs of this species of fish is important.

Read on to find out everything you need to know about silver arowana care, and possibly keep one of these fish in your own freshwater aquarium!


Osteoglossum bicirrhosum is commonly known as the silver arowana, which is sometimes written as arahuana. They were also known as "monkey fish" because of their ability to jump out of the water and catch prey and "dragon fish" because of their large scales. These fish have received several other scientific descriptions since their discovery, including Osteoglossum vandelli and Ischnosoma bicirrhosum, and can still be referred to as such depending on the source.

Silver arowanas belong to the Osteoglossidae family, which is often defined as a freshwater fish species with a "bony tongue". These types of fish have a bone structure at the bottom of their mouth that is equipped with teeth that are used to push food against the top of the cavity. They are also classified as true bony fish, which means the rest of their skeleton is made up of bones rather than cartilage.

Fossil records of Osteoglossidae species go back 150 million years.

Natural habitat

Silver arowanas are found in many parts of North South America, including Brazil, Colombia, Peru, Ecuador, Guyana, and French Guiana. In particular, they were documented in the catchment areas of Essequibo, Oyapock and Amazon.

It is common to find silver arowanas up in slow moving and still areas where they can forage in and out of the water for prey. These ecosystems also usually have blackwater conditions, with tannin-colored water from fallen debris and branches from the jungle canopy above. Silver arowanas are facultative air breathers, which means that in poor water conditions they can breathe atmospheric air if necessary.

It is believed that silver arowanas migrate with the dry and rainy seasons. During the dry season, they tend to stay in quieter areas, such as those found in tributaries and lagoons. As soon as the rivers swell with rain, these fish move to the larger waterways where the food is more abundant.

Some silver arowana have been caught in non-native waters in the United States, although these populations are not currently believed to be self-sufficient. Most likely, these sightings are the result of aquarium releases due to the heavy maintenance and care of the tank.

Silver arowanas are also prepared as a dish in some areas around their river ecosystems. Because of their popularity both in the hobby of fish farming and because of their importance for the local diet, the wild populations of these fish are monitored and harvest regulations are enforced.


The silver Arowana is easy to identify, but can sometimes be a little difficult to distinguish from other similar Arowana species. Real silver arowanas have relatively large silver scales that take on an almost metallic sheen. They are sometimes referred to as "dragon fish" because they have a mythical appearance that is similar to that found in folk creatures.

Silver arowanas have a long and slender body; Their dorsal and anal fins start about three-quarters of the way down from their head and extend to their tapered caudal fin. They have a remarkably large, downward-facing mouth that easily draws in food.

The silver arowana (Osteoglossum bicirrhosum) is sometimes confused with the black arowana (Osteoglossum ferreirai), especially in adulthood. Juvenile silver arowana has a dark side line, while juvenile black arowana has darker features overall, which are most noticeable in the fins. Adult silver arowanas and black arowanas are a little more difficult to tell apart. The main differences are in the number of dorsal rays, anal rays and the number of vertebrae.

In general, the best way to guarantee the type of fish is through a reputable seller. However, you can also tell by looking at your body shape and behavior if you know what to look for. Silver arowanas tend to have a much fuller and lighter body than black arowanas, and appear to be a bit more territorial in a tank setting than their darker counterparts.

How big do silver arowanas get?

These South American fish are often referred to as monster fish, but how big do they really get?

The silver arowana can easily reach more than 36 cm in length, although it is unclear how long it can actually get. One of the largest silver arowanas in captivity has already reached the 48cm mark!

Most fish, however, are sold as fry and look completely manageable when they are still small. The truth is, in the early stages of their life, these fish can grow about 5.1 cm each month! There is no way to keep a silver arowana in a temporary tank.

In addition to their size, silver arowanas can also live a very long time. It is believed that under ideal conditions they can easily live in the fish farming hobby for more than 10 years. Unfortunately, not many hobbyists are able to consider the tank size and lifespan of these fish, and they are donated to aquariums or given to non-native waters.

Is it illegal to own silver arowana?

As one of the most common types of monsters in the freshwater aquarium trade, you may be wondering whether it is even legal to own such a fish!

South American silver arowanas are for the most part legal worldwide. However, it is important to follow local regulations regarding the species, even if the seller insists it is legal to do so. Some jurisdictions may require permits, while others may have bans on certain Arowana species entirely.

One of the most notable types of arowana to be banned from international trade is the Asiatic Arowana (Scleropages formosus), also known as the Asiatic Bonytonue or Asiatic Dragonfish. The Asiatic Arowana is classified as endangered due to the decline in population due to habitat destruction.

What does a silver arowana cost?

The price of a silver arowana depends on the size and quality of the fish. Hatchlings are typically for sale online for $ 50, while larger fish cost more than $ 200. Other color options and / or the quality of the breed can be achieved for more money.

While this doesn't seem like much for such an impressive fish, as we will discuss, tank setup and maintenance can get quite challenging and expensive for this species. Also note that legal permits may incur additional costs.

Requirements for the silver arowana tank

Silver arowanas can be over 92 cm long. This means that both the length and the width of the tank must be greater. The altitude must also allow the fish to naturally establish an area in the upper water layers of the tank. This means that an aquarium of at least 946L is recommended to accommodate teenagers and adults. In general, the best tank has dimensions that allow the fish to turn around comfortably and display natural predatory behavior.

Otherwise, they don't need too much to be happy. Because they work best in larger tanks, adequate filtration and water agitation are required for nutrient export and gas exchange. Their metallic colors reflect best on a dark surface, but can also be stored in a tank with a bare bottom.

Floating plants and vegetation are valued as these fish spend most of their lives just below the surface of the water. Decorations should be minimal to give your fish as much swimming space as possible.

To do justice to the extreme size of these fish, some hobbyists have chosen to keep them in a pond instead of an aquarium. Some have even converted above-ground swimming pools into a pond for their monster fish! Because silver arowanas naturally jump out of the water to catch prey in their South American ecosystems, a protective net is recommended for both pond and tank structures to keep your fish from jumping out while avoiding injury.

Water parameters

Silver arowanas are native to the tropical river ecosystem of South America and can be quite robust in terms of water conditions. These fish require a stable water temperature between 23.9 and 27.8 ° C (75 to 82 ° F) with a relatively neutral pH between 6.0 and 7.0.

Although they are usually seen in calm water, they can withstand moderate water flow.

Silver Arowana tank mates

Although they are large fish, Silver Arowana can actually be kept with a variety of fish species. As we'll see, adults are better at handling less aggressive species, and teenagers can actually be quite fragile in their early stages. For this reason, it's best to keep juvenile silver arowanas in a relatively quiet tank until they reach 5+ inches (12.7+ cm).

It's also important to keep in mind that silver arowana stays on the surface of the water almost all of the time. When filling your tank, use middle and lower water column floats to avoid aggressive interactions.

Which fish can live with silver arowanas?

In general, predator tanks are large and not very diverse. This means that your silver arowana tank will look a little empty at first and will only contain a handful of fish. It is important to keep in mind that most of the tank mates listed will reach impressive sizes even when fully grown and it will take some time to fill your tank completely!

Some of the best tank mates for silver arowanas are:

  • Gars (Lepisosteiformes order). Gars are slender bony fish that date from the late Jurassic period. They are usually easy to spot by their elongated jaws. Tropical Gar (Atractosteus tropicus), Florida Gar (Lepisosteus platyrhincus), and Cuban Gar (Atractosteus tristoechus) have proven to be successful tank mates with the silver arowana.
  • Giant gourami (Osphronemus goramy). The giant gourami is usually a fish to avoid when raising fish, but it's actually good in silver arowana tanks. In captivity, giant gouramis grow to be approximately 16 inches at their mature size and require a 757 liter (200 gallon) aquarium or more. However, their calm and lonely lifestyle make them a good pairing for Arowana.
  • Freshwater stingrays. Stingrays should only be kept by hobbyists who are experienced in keeping Elasmobranches, as they require special care and attention. Common Arowana pairings are motor stingrays (Potamotrygon motoro) and black diamond stingray (Potamotrygonidae family). Note: Stingrays are banned in many states and countries for commercial reasons.
  • Bichir dinosaur (Polypterus senegalus). Another prehistoric fish, the dinosaur Bichir, can grow to be almost 61 cm long. They have special pectoral fins that they use to slide across the bottom of the aquarium so that your silver arowana remains undisturbed above.
  • Clown knifefish (Chitala ornata). Knifefish are very different and at first glance don't even look like a species of fish. They don't have scales or fins! However, clown knifefish can grow to be 12 to 24 inches long and require plenty of space to swim.
  • Clown Loaches (Chromobotia macracanthus). It is common for clown loaches in the form of small carapaces and small quantities to be improperly handled. However, a silver Arowana carapace is just what they need to thrive and lead a fulfilling life. While they look tiny when you first bring them home from the aquarium, these fish can grow to be over 12 inches in length. They also need to be kept in schools that need a very large tank!

Silver Arowana behavior

Adult silver arowana are solitary fish; They like to stay in the upper water column and feed on small fish, invertebrates and other animals. They can become aggressive towards fish that also prefer the upper water column. It is best to avoid other surface swimmers.

They can also become aggressive towards other similar looking fish. Otherwise you can see them sliding effortlessly back and forth under the surface of the water, waiting for food.

Juvenile silver arowanas are actually prone to being bullied by other fish. It is usually recommended that you keep your juvenile arowana in more peaceful species first or in a different tank so it can grow out.

In the wild, these fish are known to jump out of the water to eat large insects and sometimes even small mammals and birds. For this reason, it is best to always have a net over the aquarium or pond.

Silver Arowana Diet

Feeding such a large fish can be difficult and expensive. These fish are known to be somewhat picky eaters in the early stages of their aquarium life. The silver arowana is primarily a carnivore that hunts other fish and insects of considerable size. However, it has also been documented that they eat fallen fruits and nuts from the jungle roof in the wild.

As a teenager, silver arowanas can be fed smaller foods. However, you should get a varied diet, including live and frozen foods. While they are small, worms (blood worms, earthworms, Tubifex worms), krill, mosquito larvae, and fish flakes / pellets may be offered.

As they grow, you can offer live, frozen, and freeze-dried foods. Freeze-dried foods don't contain many essential nutrients to promote growth and should be avoided until your fish is at least a year old. Worms (blood worms, earthworms and Tubifex worms) can still be fed together with krill, fish flakes and pellets. However, you can also offer larger prey such as insects (crickets and mealworms), other invertebrates (mussels, clams, prawns, shrimps), fresh pieces of fish or even live food fish.

Note: only use feeder fish if you have a reliable supplier. Feeder fish are known to transmit diseases and parasites and can potentially infect all fish in your aquarium!

Breeding silver arowanas

Because these freshwater fish are so large and can become territorial to one another in a small space, captive breeding is usually not possible.

In the wild, these fish spawn at the beginning of the rainy season. The adult fish form pairs and the female lays the eggs. The male then takes the eggs in his mouth, where they later hatch. It takes about two months for the eggs to ripen into fries on their own. After that, they can find food and take care of themselves.

Because these fish are such an impressive size, their brood size is actually considerably smaller than that of most other freshwater fish. Female fish only lay a few dozen eggs at a time and a few hundred each season.


Silver arowanas are one of the most popular types of monster fish currently available from aquarium stores. While they don't require much additional care than other freshwater fish, their size, lifespan, and diet make them difficult to accommodate indefinitely.

Never buy a silver arowana if you haven't had the funds to create a home for up to 20 years!

If you have any questions about keeping silver arowanas or other large South American species, or if you have experience keeping these monster fish in your own aquarium, don't hesitate to leave a comment below!

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