Arowana Fish: Care, Diet, size, & More

Arowana is a well-known species in the aquarium hobby. This large and aggressive fish comes in several beautiful colorations, patterns, and types. Depending on the area this ancient fish live, they might look slightly different but they all are large species that hunt and feed on smaller species. 

This guide will cover the types, care requirements, and all you need to know about this species. We’ll also provide you with the best practices to make this fish thrive under your care.

Species Profile & Overview

The Arowanas are beautiful freshwater fish belonging to the subfamily Osteoglossinae. This family are known as bony tongue fish because of the structure of their mouth. Arowana, same as other species in this family, has a bony head and a body that is covered in hard overlapping scales.

The lower jaw or the floor of the Arowana’s mouth has a flat bone that is covered with tiny teeth which is why they are called “bony tongue” or “bonytongues” fish. Despite the name, they do not have a “tongue” and this is just a term to distinguish them from other species.

Arowanas can be found in most parts of the world including South America, Asia, Africa, and Australia. In the aquarium trade, the Asian Arowana and the South American Arowana (Silver Arowana) are the most common types. 

The Asian Arowana is the most colorful of all other Arowana species and is sold at much higher prices. Unfortunately, Asian Arowana is banned in the United States but they are allowed for import in most other countries including Canada. 

This Species can breathe in and out of the water which makes them hardy fish. When oxygen levels go down the Arowana will come to the surface of the water and gulp air into its swim bladder. The swim bladder of these fish is covered with fine blood vessels, like lung tissue, that can absorb oxygen.

These beautiful pets are not beginner fish as they need a large aquarium with special care. They are also very aggressive and solitary species that only allow company when they are young. This makes them slightly hard pet to keep. 

They are omnivores but predatory species that will hunt any smaller fish they can fit in their large mouth. They tend to get aggressive when they are kept with other species that swim in the same region of the water. These giants should only live in large aquariums and only with similar-sized fish that have the same personality.


Red Tail Asian Arowana
Red Tail Asian Arowana

Arowanas have a unique slender body shape that is stretched horizontally. Because of their lengthy looks, they are known as “Dragon fish” in Asian countries. Having an Arowana is a status symbol in these countries and is often believed to bring good luck and prosperity.

The Asian, Australian, and African variants are very similar in terms of their body shape. But the South American Silver Arowana is developed to look slightly different. Silver Arowanas, unlike Asian Arowana, are more lengthy and have dorsal and anal fins that are stretched along the top and bottom of their body.

To learn more about types of this species you can read our article on Rare & Expensive Types of Arowanas. All Arowana have Large overlapping scales that cover their body. They also have a bony head that is occupied with a boney mouth. 

Arowana fish are sexually monomorphic which means both genders look exactly the same. Their many different approaches to identifying the sex of Arowana fish but they all are somewhat guesswork. 

The best way to identify the sex of an arowana is to look at their anal vent and mouth when they are adults. The females have a larger vent designed to lay eggs but males have a round mouth designed to hold the fry while growing.

Since Asian Arowana is extremely popular in the hobby, many breeders in Asia have line-bred them to develop beautiful coloration. They are now available in full red, orange, gold, platinum, black, and other colors.

Asian Arowana Vs Silver Arowana

The Asian Arowanas ( Scleropages formosus ) are more colorful and girth in comparison to the silver Arowana ( osteoglossum ) from South America. The anal and dorsal fins are also very different. Asian Arowana has smaller fins that are pushed towards the tail fin whereas silver Arowana has long fins that almost cover the entire back and lower part of their body.

Silver Arowanas are also slightly narrower and get even more narrow towards the tail. They will also grow lengthier and only come in silver color. 

Adult Size

Arowana fish can grow up to 3 feet in length. The Asian Arowana often stays shorter at around 1 – 2 feet but they are more girth and heavy. Silver Arowanas will easily grow to 3 feet when they have adequate space and a proper diet. 

Because of their lengthy size, they should be kept in large aquariums and are not beginner fish. They will grow fast and reach their max size when enough food is available. So if you have a small tank they will soon outgrow your tank. 


Arowanas live long lives and can live more than twenty years in captivity. A healthy Arowana can live a long life so a long-term commitment is required to own this fish. 

When they receive clean water, a diet, and a spacious tank, you can expect them to easily reach and cross the 20 years mark. 

Keep in mind that things like genetics and external factors can lower their expected lifespan. Diseases are the main cause of these majestic pets experiencing premature deaths. So we highly recommend focusing on the quality of the water to ensure your fish doesn’t get sick. 

Super Red Asian Arowana in a bare bottom aquarium
Super red Asian Arowana

Behavior and Temperament

Arowanas are naturally aggressive and predatory fish. They are solitary fish and prefer to live alone. However, they will not fight with fish that are swimming in a different section of the tank. They are often calm and mind their own business when kept with similar-sized species.

Arowanas usually swim near the top section of the water where they can hunt on the surface of the water. Their mouth is pushed upwards which will assist them in hunting small creatures of the surface of the water.

This species are also slightly skittish and should be kept in quiet places to prevent stressing them. Exposing your fish to busy and nosy areas will cause the fish to develop diseases and even sudden death.

Arowana Care

Arowana is easy to care for as long as you give them adequate space. It’s also important to mention that arowanas are not beginner-friendly. So you will need to know the basics of keeping predatory fish to keep them happy. 

The tank environment and water conditions of your aquarium are also important. In this section, we will guide you through all the information you need to create a better living space for this beautiful fish. 

Tank Size

Arowana is a large species so they need a tank that is at least 250 gallons. The tank needs to be long so your fish can have enough horizontal space to swim. The width of the tanks must be 2 feet or more so it can easily make a turn when reaching the end.

This species grow super lengthy and need enough space to maneuver around. in fact we recommend making an indoor pond if you have the space and budget. A large pond will give your pet Arowana a lot of room to swim and play. 

What To Put In An Arowana Tank

Arowanas love open areas where they can swim with ease. This is why it is ideal to get them the biggest aquarium possible and avoid adding too many decorations. An aquarium that is too cluttered with decorations is not a good choice for this fish. 

Arowana fish are coming from tropical regions of the world where water is warm and plants can grow naturally. This means the best tank environment is a tank that has similar conditions as its natural habitat. Keep in mind that having live plants in a large aquarium is not an easy task if not done right. 

When it comes to choosing plants, you can pick any large type of plant you wish to add to your aquarium. Arowana fish are not picky and will not disturb the plant if you place them right. The plants need to be in the background and on the sides of the tank leaving the middle free. 

We recommend decorating your aquarium with plants only unless you have a large space that can accommodate a few large decorations. Arowanas are expensive pets and by adding decorations you are risking skin injuries. It is rare for these fish to get injured, but it can happen; especially if you have sharp decor.

Fine gravel or sand is ideal to use as the substrate for your tank. If you want to use root-feeding plants, you will need to add root tabs as sand and gravel do not have any nutrients. One or two inches of substrate will be just the right amount to keep your plants in place. 

hard leave plants, such as anubias, can also make a great option to add to your tank. These plants are hardy and can live in any lighting conditions. There are also many other types of plants that do not require substrates.

To learn more about live aquarium plants you can follow this link: Best Aquarium Plants 

Even though we recommend having plants with your Arowana, most people prefer to have a bare tank with no substrate or decorations. A bare tank will draw all the attention to the fish which most prefer. In most cases, a black background tank will bring out the true beauty of your Arowana fish.

Arowanas are also great at jumping out of the water. In the wild, they jump out of the water to hunt insects off the tree branches and leaves. Their long and springy body makes it easy for them to jump a few feet out of water. This means you must have a lid, with a locking mechanism, covering your aquarium or pond at all times. 

Red Tail Asian Arowana
Red Tail Asian Arowana

Water Parameters

Arowana is adapted to live in warm tropical regions of the world. So your tank should have a similar environment for them to thrive. 

Even though arowana can breathe air, the water has to be well-oxygenated. They will mainly breathe from water and air is not their primary way of breathing. The beneficial bacteria in the tank will also need oxygen to live so a well-oxygenated tank is a must!

The water movement should be moderate so your fish can swim without trying to fight with the water. To give your fish the best living environment make sure your tank parameters fall within the following range:

  • Temperature: 75 – 85 Degrees Fahrenheit 
  • PH: 6.0 – 7.0
  • TDS: 50 – 200 PPM

We find the best temperature for our Asian Arowana to be around 82 degrees Fahrenheit and the pH at 6.5. Tho your water conditions can be different.


Lighting is the key when it comes to keeping Arowana. These beautiful pets need a good light source to display the true beauty of their coloration. 

There are many different lights available in the hobby but you should pick a light based on the color your fish have. If you have silver Arowana you are in luck because most lights will just work fine. 

For more rare and colorful Arowanas such as red or gold Asian Arowanas, you will want to pick a light that has blue and red colors. Blue and red colors will bring out the red coloration of your fish and make it pop out in the tank. 

Some use tanning lights which we do not recommend. They might make your Arowana look more beautiful, but they are not natural and might harm the fish in the long run. 

Having an LED light on a timer is the best way to light your aquarium. You should set the timer to turn on and off at specific times of the day to resemble a day and night schedule. Most LED aquarium lights have timers built in which makes this job easy.

Filtration System

Arowanas are carnivore species and eat meaty foods. This means they will produce large amounts of waste for your filter to clean. Carnivore species can easily and quickly pollute the waters if the filtration can not keep up with the waste production.

Arowanas are expensive fish so you shouldn’t risk their health with a low-quality filtration system. Fortunately, there are many good quality filters that can keep up with the waste Arowanas make. Depending on the size of the tank you have, you might want to have one or more filters running simultaneously to keep the water quality up at all times. 

When picking a filter your main focus should be on the number of times per hour it can circulate the water and how much room it has for the beneficial bacteria to grow. Usually, larger filters are more powerful to filter the water better and faster. 

FX6 Canister filters and Sump Filters are our top choice of filters for an Arowana tank. Both of these systems have the potential to keep the tank neat and clean. As mentioned, depending on the size of the tank you have you might want to get more than one filter. 

Common Arowana Diseases & Health Issues

Despite their large size, the Arowana fish is susceptible to all common aquarium diseases. These fish are at risk of getting infections, parasitic diseases, internal worms, ich, and many more illnesses. They also get cosmetic diseases like drop eye disease that will cause the fish’s eyes to pop out. 

Barbels Infection or Hemorrhoids is another infection type of disease that only affects Arowana. Barbels Infection, as the name suggests, is a small growth on the two small barbells these fish have below their lips. 

This infection usually happens when the fish is kept in a small tank. When fish swims fast towards the end of the tank they can hit the glass or other obstacles which will cause injuries on their babels that can lead to infections. Some Arowanas will also rub their barbels against the tank glass or decorations. This bad habit will easily turn into an infection. 

The cloudy eye is also another common disease among Arowanas. This disease will cause a whitish-gray film over Arowana’s eyes. If this disease is not treated quickly, it will cause the fish to become completely blind or even cause other internal or external diseases. You must see a professional vet to treat this properly and quickly. 

Arowana can produce a large amount of waste, so things can go wrong if you keep them in a small tank. Most of the diseases we mentioned are linked to ammonia and poor water quality. You must keep these fish in pristine water to ensure their long-term health.

Diet and Feeding Requirements

Arowanas are omnivores but predatory fish. Small aquatic creatures and insects are their main source of food in the wild. They often hunt near the surface of the water and catch any small creatures they can fit in their mouth. 

They also hunt for insects above water. They will jump and catch any small insects clinging to the leaves and branches of the trees. They will also eat plant matter but this is a small part of their diet and only when they can’t find enough food.

In captivity, these majestic and beautiful fish are not picky eaters. They will happily eat any high-protein pellets or fish food you give them. But ideally, you will want to feed them a mix of different fresh or frozen foods.

Raw shrimp and muscles are great foods you can buy from the supermarket to feed your Arowanas. They can also eat Beefheart when properly prepared and blended. 

At younger ages, it’s best to feed them frozen foods available in pet stores. But as they grow they can receive muscles, shrimps, and Beefheart. You can also feed them small feeder fish to sharpen their hunting skills. 

Because Arowanas grow super fast at younger ages, you will want to feed them 2 – 3 times per day. They should only receive low amounts at each feeding session so it doesn’t affect the water quality. 

Adult Arowanas, however, do not need as much food as they are no longer growing. They will only eat if they are hungry so it’s easy to find out how often your adult Arowana wants to eat. Adults usually want to eat every day or every other day. 

Because this species only eat when they are hungry, you should never leave uneaten food in the tank. Only feed the fish what it wants to eat and remove all the leftover foods immediately.   

Tank Mates

Arowanas are large predatory fish and must live with the same type of species. Remember to only keep one Arowana per tank as they tend to fight with each other. However, if you have a large pond you can ignore this fact and add more than one. 

Arowanas are known to be territorial so you should only attempt to add more fish if you have enough space for all. If you decide to have more fish, you will need to add a lot of them to prevent territorial behaviors. A crowded tank makes it hard for the Arowana to pick a spot as their territory. 

All the species also need to be around the same size with no extraordinary aggression issues. When adding new fish, you will need to watch the tank closely for a few days to see if they get along or not. Adding new fish to a predatory tank or pond is always risky!

Considering all the points we mentioned, here are our top tank mates for Arowana:

Super Red Asian Arowana in a bare bottom aquarium


Arowanas are extremely beautiful species of freshwater that can grow quite large. If you are into predatory fish and have a large tank, then we definitely recommend keeping this species. Arowana species are not cheap nor are beginner level pets so you should only attempt to keep them if you have enough experience keeping predatory fish. They can be great pets but they demand a lot of initial investment and a long-term commitment to care for them.

We also answered some of the most frequently questions asked about arowana questions. You can find them here: Commonly Asked Arowana Questions

Systematic Approach to Arowana Gender Identification…
Silver Arowana
Deciphering the Evolutionary History of Arowana