Battle of the Titans: Arowana vs Arapaima

Arowana and Arapaima are two fascinating fish species often mistaken for each other in the aquatic world. While they share some common traits, such as their ancient roots and unique mouth structures, these tropical titans also possess distinct behavior patterns and physical characteristics that set them apart.

This article offers an insightful comparison of Arowana vs Arapaima – from their origins to behaviors, answering all your curiosities about these awe-inspiring aquatic creatures.

Hold on tight! Your journey into the mesmerizing underwater realm starts here.

Key Takeaways

  • Arowanas and Arapaimas have ancient origins, unique mouth structures, and surface-dwelling tendencies.
  • Both fish species can breathe air using specialized organs, but they have different adaptations for this ability.
  • Arowanas are strictly freshwater dwellers, while Arapaimas can tolerate both freshwater and brackish water.
  • Arapaimas are much larger than Arowanas, with the ability to grow up to 10 feet long and weigh over 400 pounds.

Similarities Between Arapaimas and Arowanas

Arapaimas and Arowanas share ancient roots, unique mouth structures, surface-dwelling tendencies, and the ability to breathe air.

Ancient Roots

Both Arapaimas and Arowanas hail from venerable lineages, tracing their ancestry back to the Cretaceous period, around 100 million years ago. Emerging as two fascinating fish species with remarkable survival capabilities, they have evolved distinct adaptations that make them kings of their freshwater domains.

Embedded in their ancient roots is a captivating tale of evolution over millions of years. Interestingly, African Arowanas are more genetically similar to Arapaimas – a twist in aquatic genealogy that further underscores their ancient connections! Indeed, studying these magnificent creatures throws open the doors to understanding how life thrived amidst prehistoric ecosystems and climatic changes.

Unique Mouth Structure

Arowanas and Arapaimas stand out from other freshwater fishes due to their unique mouth structure. Both species have elongated jaws that allow them to capture prey effectively. The Arowana’s mouth is slightly upturned, resembling a “sword-like” shape, while the Arapaima has a more pronounced jawline with sharp teeth.

This distinctive feature enables these fish to swiftly snatch their prey from the water’s surface. They are skilled at hunting insects, small crustaceans, and even smaller fish that venture too close to the surface.

Their upward-pointing mouths make it easier for them to grab food without submerging their entire bodies.

The bony tongues of Arowanas and Arapaimas also play an essential role in capturing prey. These structures help propel food towards the back of their throats by providing support during suction feeding.

This remarkable adaptation ensures efficient consumption of meals.

Surface Dwellers

Arowanas and Arapaimas are both surface dwellers, meaning they prefer to spend their time near the top of the water. This behavior is due to their unique ability to breathe air. Unlike most fish that rely on gills for oxygen, these freshwater species have a specialized organ called a labyrinth organ that allows them to extract oxygen from the air above the water’s surface.

Both Arowanas and Arapaimas will frequently swim close to the water’s edge, often breaking through its surface to take in gulps of air. This adaptation enables them to survive in environments with low oxygen levels or stagnant waters.

It also gives them a distinctive appearance as they gracefully glide just below or above the waterline.

Their surface-dwelling behavior also makes Arowanas and Arapaimas excellent jumpers, capable of leaping out of their tanks if not provided with adequate space or proper lid coverings.

Therefore, it is important for aquarists who keep these magnificent creatures to ensure their aquariums are secure and offer enough room for these active swimmers.

Air Breathers

Arowanas and Arapaimas are both remarkable fish in the sense that they have a unique ability to breathe air. Unlike most other fish species, these two can take in oxygen directly from the atmosphere using specialized structures.

Arowanas possess a modified swim bladder that acts as a primitive lung, allowing them to extract atmospheric oxygen when necessary. Arapaimas, on the other hand, have an accessory breathing organ called a labyrinth organ located in their gills.

This organ enables them to extract oxygen from air bubbles at the water’s surface. Both of these fascinating adaptations allow Arowanas and Arapaimas to survive in low-oxygen environments and make them particularly suited for life near the water’s surface.

Colorful Creatures

Arowanas and Arapaimas are not only fascinating creatures, but they also captivate our attention with their vibrant colors. Arowanas are known for their striking hues ranging from shimmering gold to deep red, making them a true standout in any aquarium.

On the other hand, Arapaimas exhibit an enchanting combination of greens and blues that glisten under the light. These two species definitely bring a colorful splash to your aquatic habitat and will be sure to capture the attention of anyone who lays eyes on them.

Arowana vs Arapaima – Differences

Arapaimas and Arowanas have distinct differences in their origins, water habitats, size, hunting techniques, social behavior, parenting styles, and legal status.

Different Origins

Arowanas and Arapaimas have distinct origins. Arowanas are native to Southeast Asia, primarily found in rivers and wetlands of countries like Thailand, Indonesia, and Malaysia. On the other hand, Arapaimas are indigenous to South America, specifically the Amazon River basin.

These two freshwater fish species have evolved in separate environments over time, resulting in differences not only in their physical characteristics but also in their behaviors and habitat preferences.

Understanding their different origins provides valuable insight into how these amazing creatures have adapted to their respective ecosystems.

Water Habitat (Freshwater vs. Brackish Water)

Arowanas and Arapaimas, while both fascinating to aquarists, have different preferences when it comes to their water habitats.

FishWater Habitat
ArowanaArowanas are strictly freshwater species. They inhabit rivers, swamps and flooded forests in South America, Southeast Asia, and Australia.
ArapaimaArapaimas, on the other hand, can tolerate both freshwater and brackish water. They are native to the Amazon and Essequibo basins of South America, where they navigate across different water types.

These habitat preferences mean that, in an aquarium setting, Arowana and Arapaima water conditions must be tailored to mimic their natural environments.

Size (Enormous Size of Arapaimas)

Arapaimas are known for their enormous size, making them one of the largest freshwater fish species in the world. These mighty giants can grow up to 10 feet long and weigh over 400 pounds! In comparison, Arowanas typically reach a maximum length of around three feet.

The sheer size difference between these two fish is quite remarkable and definitely something to consider when it comes to tank size requirements. Arapaimas need spacious tanks with plenty of swimming room to accommodate their massive bodies, while Arowanas can thrive in slightly smaller environments.

So, if you’re looking for an awe-inspiring showstopper in your aquarium, the Arapaima’s impressive stature won’t disappoint.

Hunting Techniques

Arowanas and Arapaimas have distinct hunting techniques that set them apart from each other. Here are the different ways these two freshwater fish capture their prey:

  1. Arowana’s Hunting Technique:
  • Arowanas are known for their exceptional jumping ability, allowing them to catch insects and small animals that venture near the water’s surface.
  • With keen eyesight, they patiently stalk their prey from below before launching themselves out of the water to snatch it with their powerful jaws.
  • They primarily rely on ambush tactics, lurking in the shadows or among aquatic plants, waiting for an opportunity to strike.
  1. Arapaima’s Hunting Technique:
  • Arapaimas are true apex predators and employ a unique hunting technique known as “gulp feeding.”
  • These massive fish have a large mouth equipped with teeth-like structures called “gill rakers” that allow them to filter-feed on smaller prey.
  • Using suction generated by their expansive mouths, Arapaimas rapidly inhale water along with any nearby prey, swallowing everything in one swift motion.
  • They mainly consume smaller fishes, crustaceans, and even small birds or mammals that come too close to the water’s edge.

Social Behavior

Arowanas and Arapaimas have distinct social behaviors that set them apart from each other. Arowanas tend to be solitary creatures, preferring to swim alone rather than in groups. On the other hand, Arapaimas can often be found in shoals, swimming together as a unit.

This difference in social behavior is reflected in their hunting techniques as well. Arowanas are skilled hunters, known for their ability to leap out of the water to catch prey above the surface.

In contrast, Arapaimas are ambush predators that rely on stealth and patience to capture their food underwater. These unique behaviors highlight the diverse characteristics of these fascinating freshwater fish species.

Parenting Styles

Arowanas and Arapaimas have distinct parenting styles that set them apart. Arowanas are mouthbrooders, meaning they carry their eggs or fry (baby fish) in their mouths until they hatch and the fry are ready to swim on their own.

This unique behavior ensures the safety and protection of the young ones from potential predators. On the other hand, Arapaimas exhibit a different approach to parenting by building nests made of vegetation where they lay thousands of eggs.

Unlike Arowanas, Arapaima parents do not provide direct care for their offspring once the eggs hatch. Instead, they rely on external factors such as water currents to protect and nourish the young ones.

Legal Status

Arowanas and Arapaimas have different legal statuses, which can vary depending on the country or region you live in. In some places, owning either of these fish may be restricted due to their endangered status or concerns about their potential impact on local ecosystems if released into the wild.

For example, in certain countries, like the United States, it is illegal to own Arapaimas without special permits because they are considered an invasive species that could harm native wildlife.

Arowanas, on the other hand, are not as heavily regulated but there may still be restrictions on importing or exporting certain species due to conservation efforts. It’s important for aquarists to familiarize themselves with the laws and regulations governing the ownership of these fish before considering bringing them into their aquariums.

Can Arapaima and Arowana Live Together?

Are you wondering if Arapaima and Arowana can coexist in the same tank? Find out the challenges, water requirements, and safety considerations of keeping these fascinating freshwater fish together.

Dive into our blog to learn more!

Challenges of Keeping Them Together

Keeping Arowanas and Arapaimas together in the same tank can pose several challenges for aquarists. Firstly, these fish have different water requirements. Arowanas are adapted to freshwater habitats, while Arapaimas prefer brackish water environments.

Maintaining the ideal conditions for both species simultaneously can be difficult.

Secondly, their size difference is another challenge. Arapaimas are known for their enormous size, growing up to 10 feet long and weighing over 400 pounds. On the other hand, Arowanas are relatively smaller.

This significant difference in size makes it crucial to provide a tank that is spacious enough to accommodate both species comfortably.

Lastly, safety considerations should not be overlooked when keeping these two fish together. Arapaimas are predatory by nature and may see smaller Arowanas as potential prey. Therefore, aggression or territorial disputes can arise between them if they feel threatened or hungry.

Water Requirements

Arowanas and Arapaimas have different water requirements, which aquarists need to consider when keeping them in captivity. Here are the key factors to keep in mind:

  1. Temperature: Arowanas prefer warmer water temperatures ranging from 75°F to 86°F (24°C to 30°C). On the other hand, Arapaimas thrive in slightly cooler waters that range from 68°F to 82°F (20°C to 28°C).
  2. pH Level: Arowanas require a pH level between 6.5 and 7.5 for optimal health and well-being. Arapaimas, however, prefer a more acidic environment with a pH level ranging from 5.5 to 6.5.
  3. Water Hardness: Arowanas can tolerate a wide range of water hardness levels, but they generally do well in moderately hard water with a range of around 8-12 dGH (degrees of General Hardness). On the contrary, Arapaimas thrive in soft water conditions with low hardness levels (around 2-6 dGH).
  4. Filtration System: Both species require excellent filtration systems to maintain clean and healthy water conditions. It’s important to choose the appropriate type of filtration system based on their specific needs.
  5. Tank Size: Due to their large size, both Arowanas and Arapaimas require spacious tanks that can accommodate their length and swimming habits. Arowanas need at least a 150-gallon tank for smaller individuals, while larger specimens may need significantly larger tanks or even custom-built aquariums. Arapaimas require an enormous amount of space due to their immense size and should ideally be kept in ponds or massive aquarium setups.

Safety Considerations

  • It is important to consider the safety of both the Arowana and Arapaima when keeping them together in the same aquarium.
  • The size difference between these two fish can pose a risk, as Arapaimas can grow much larger than Arowanas and may potentially harm or even eat smaller fish.
  • Arowanas have been known to exhibit aggressive behavior towards other tankmates, so it’s crucial to ensure compatibility with other species before introducing them into the same tank.
  • Due to their predatory nature, both Arowanas and Arapaimas may consume smaller fish or invertebrates that are housed in the same tank. Therefore, it is necessary to carefully choose tankmates that will not be seen as potential prey.
  • Providing ample hiding spots and structures within the tank can help reduce stress and aggression among different fish species. This can be achieved by adding live plants, rocks, or driftwood.
  • Water quality is also paramount for the well – being of these freshwater species. Regular water testing and maintenance should be conducted to prevent any potential health issues caused by poor water conditions.
  • It is recommended to closely monitor the behavior and interactions between Arowanas and Arapaimas if they are cohabitating. If any signs of aggression or stress are observed, it may be necessary to separate them into individual tanks for their safety.
  • Remember that while it is possible for some aquarists to successfully keep Arowanas and Arapaimas together in an appropriate-sized tank with proper care, it requires careful consideration of their specific needs and behaviors.

By implementing these safety considerations, aquarists can create a suitable environment for both Arowanas and Arapaimas while minimizing any potential risks or conflicts that may arise from cohabitation.


In conclusion, Arowana and Arapaima may share some similarities in traits and behaviors, such as their ancient roots and unique mouth structures. However, they also have distinct differences in their origins, water habitats, size, hunting techniques, social behavior, parenting styles, and legal status.

Keeping them together can pose challenges due to varying water requirements and safety considerations. Understanding these differences is crucial for aquarists interested in these magnificent freshwater species.


1. How do Arowana and Arapaima differ in their physical traits?

Arowanas have slender bodies, long dorsal fins, and large scales, while Arapaimas have more elongated bodies with a prominent snout and smaller scales.

2. What are the differences in habitat preferences between Arowana and Arapaima?

Arowanas prefer freshwater habitats such as rivers, lakes, or ponds with slow-moving water, while Arapaimas are primarily found in tropical freshwater systems like flooded forests or blackwater rivers.

3. What behavioral differences can be observed between Arowana and Arapaima?

Arowanas are known for their jumping ability to catch insects or prey above the water surface, whereas Arapaimas have a unique adaptation that allows them to breathe air using a specialized respiratory organ called a labyrinth organ.

4. Are there any conservation concerns related to Arowanas and Arapaimas?

Both Arowanas and Arapaimas face conservation challenges due to overfishing for commercial purposes, habitat destruction through deforestation, and illegal trade. Efforts are being made to protect these species through regulations and conservation initiatives.

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