Arapaima (Portugese name 'Pirarucu'; or 'Paiche', originating in Tupi language – ‘pira’ and ‘urucum’, which stand for "red fish") is one of the largest and oldest pre-historic freshwater fish in the world.
Arapaima is a predator fish that belongs to the class Actinopterygii of the order Osteoglossiformes and family Arapaimidae. The Arapaimidae family is known to be one of the world’s largest freshwater fish, and only Arapaima and the African Arowana (Greek name ‘Heterotis Niloticus’) are part of this family. The species exclusively resides in the Amazon and Essequibo basins in South-America; in recent history it has been adapted to other tropical regions such as SE-Asia where it’s considered an invasive species.
Arapaima’s genus has 4 recognized species, a 5th one which can be potentially recognized:
Arapaima Arapaima (the original, wide-spread species; which was previously classified under ‘Arapaima Gigas’)
Arapaima is 23 million years old, dating back to the Miocene Epoch; Arapaima is considered a living fossil as the evolution of the species was completed 5.3 million years ago - it's said to have remained the same since then. It has adapted to the Amazon freshwater basin, and it's considered native to the freshwater basins of South America. The fish is referred to as “The Dinosaur of Fish” due to its pre-historic nature. Arapaima is a non-migratory fish and it’s stationary in the Amazon River; the Arapaima hunts and swims within a 100km radius of its birth location.
Arapaima resides between 5°-11° North-South latitude in Northern South-America, in countries such as Brazil, Peru, Colombia, Guyana and Ecuador. They are adopted in fishing parks internationally, the largest importer being Thailand – where it’s used in fishing parks and breeding aquariums.
Arapaima can be found in the following locations:
Brazil (Amazonian rivers: Madeira river, Tapajós river, Xingu river, minor waterways surrounding the freshwater island Marajó, Araguaia river; and non-Amazonian rivers: Tocantins river, flowing directly into the Atlantic Ocean).
Peru (Pacaya river, Ucayali river).
Ecuador (Pastaza river; in the province of Cotapaxi).
Guyana (Essequibo river).
Colombia (Caquetá river).
Thailand (transplanted Arapaima can be found in many fishing parks in Thailand, where it’s kept under similar conditions as it’s native-home in the Amazon basin).
Arapaimas survive in temperatures between 25°-39°, while their ideal temperature is between °25-29. The ideal ph for Arapaima is 6.0-6.5 or slightly acidic. The fish prefer soft currents, vegetation and clear waters for visibility. Arapaimas can be found in the lowlands of the Amazon basin, and they’re almost never found in the black waters of the Rio Negro where the nutrients in the river are not enough to sustain them. They require vegetation, for they prefer to hide in the algae.
Size Of Arapaima:
Maximum Size: 12 ft. (4 meters).
Maximum Weight: 440 lbs. (200 kg).
Average Size: 3-6 ft. (1-2 meters).
Average Weight: 20-100 lbs. (10-50kg).
Arapaimas are the largest freshwater species in South America and some of the largest in the world. A German explorer named Robert Hermann Schomburgk once claimed that he witnessed a 15 foot (4.5m) large Arapaima; although his claim was never proven. Records of 12 foot (4 meter) Arapaimas were provable and frequent in the Amazon wilderness before large-scale commercial fishing in the early 20th century.
The average size of a grown Arapaima in the wilderness has decreased to around 1-2 meters. 3+ meter Arapaimas are considered rare. In aquariums, the average size is 1 meter (3 feet).
Arapaimas have different sizes depending on where they're raised: In the wilderness of the Amazon basin, they grow up to 2 meters (6 feet). In industrial aquariums, Arapaimas grow up to 50-60cm (3 feet).
The provable record weight record of Arapaima is 200 kg (440 lbs.), however, Arapaimas of that size are rarely caught. In small fishing parks, they weigh between 10-50kg (20-100 lbs.) depending on their age.
Arapaima fish have a large, elongated body which can be identified by their dark black/olive green colors; emphasized by a lot of silvery shine. The body of the Arapaimas is elongated and round in cross-section. The large scales are crescent-shaped and tend to be rust-colored with red spots, the red markings of which make them identifiable. The gender of Arapaimas is difficult to determine, however, during the breeding season the males have shinier colors and their heads are a lot darker.
The mouth is small and the tail is rounded. The iris of Arapaimas is often yellow or red. In the lateral line there are often 35 or 36 scales, and in the line adjacent to the longitudinal axis there are 3-3.5 scales on each side of the body. The dorsal fin has support of 20-24 rays, while the anal fin is longer with up to 40 rays.
Arapaimas re-emerge every 10-20 minutes to breathe; however, they can remain underwater for longer. Arapaimas can survive up to 24 hours outside of water. They swim near the surface of the water, and can dive up to 2 meters deep. Arapaimas can swim in both directions – forward and backward, making them more resilient to predators. Arapaimas have residual lungs, but they have to surface to the air in order to breathe. Arapaimas have a small upright mouth, which they use to absorb air from the surface.
Arapaimas swim to the surface and take in the air with a loud, striking sip. This makes them vulnerable to predators, as they re-appear on the surface very often. The swimming bladder of the Arapaimas has a lung-like tissue which can extract oxygen from the air. This extra respiratory organ is considered as adaptation of the Arapaimas to the oxygen-deprived rivers of the Amazon Basin.
Arapaima breeds in pairs starting as early as October and well into March - most eggs are laid during February and March. Male and female Arapaimas pair together for the mating process; the female digs up a nest in the mud over a foot deep, and then deposits the eggs in that nest. The male then comes to the nest and fertilizes the eggs with his sperm. Both can be found near the nest guarding, and the male can sometimes carry the young babies in his mouth for protection.
The average lifespan of an Arapaima is 15-20 years. Their life expectancy can be affected by the seasonal flooding; therefore they choose to reproduce during winter months when water levels are still low.
The eggs start hatching when the water level starts rising.
Arapaimas are carnivores, a predator which feeds on other fish or meat, and rarely ever consumes vegetation. Arapaimas are opportunists and feed on small animals and birds nearby, but are not known for eating humans, a myth that was propagated due to their aggressive-defensive nature and large size of the fish.
Arapaimas consume the following:
Birds (usually next to shores or low-hanging tree branches)
The nutrition habits of young Arapaimas are similar to adult ones, and they are supplied by the parents until the third month. Young Arapaimas consume insects, fish larvae and other tiny organisms.
Note: Arapaimas have few self-control mechanisms and consume food promptly. This makes them hard to fish in "catch and release" style because they swallow the hook deeper in their gut. Certain baits used in fishing parks can help lure the Arapaimas, but without swallowing the hook deeply. Most commonly, recreational fishermen use “dissolving” baits which dissolve 6 hours after they’ve been consumed.
Arapaimas have protective scales which are up to 4 inches (10cm) long. These ancient protective scales make them impervious to all piranha attacks, allowing them to swim when they're swarmed by large numbers of piranhas. The main strength of Arapaimas are their scales - the stone-hard protective layer not only repels Piranha attacks, but it devours their teeth when they try to bite into the tissue.
Arapaimas are frequently found swimming in Piranha-infested areas of the Amazon.
Warning: Arapaimas are the most powerful fish in the Amazon basin. Arapaimas are the only species known that can repel Piranha attacks without fighting. Piranhas are the most aggressive predator fish in the Amazon basin, frequently attacking humans and having a high death rate; however, Arapaimas scales repel them and destroy their teeth. Their resilience was proven to break Piranhas teeth on attack. This is why fishermen must be careful when handling large Arapaimas.
Arapaimas protective scales are comprised of 2 protective layers: The internals contain collagen, which is a hard material that is bendable. The surface levels are comprised of collagen and calcium, a material with the equivalent strength of dried cement. Arapaima teeth are also covered in collagen, giving them a tactical advantage on their attacks. Arapaimas can be physically aggressive and threatening when they feel trapped in water, or when they're protecting their eggs. They are known to jump out and can kick a human in the face, which might prove fatal. Inside the water, they are patient hunters but outside they are fast-moving and unpredictable.
The native tribes of the Amazon river have hunted these species for millennia; and the process intensified during the early 20th century when large-scale commercial fishing vessels first came to the Amazon basin. They are hunted using spears or hunted in large nets. The average extraction rate for the early 1900's was almost 7,000 tons per year. They became easy targets for commercial fishing vessels due to their surface response which made them vulnerable as they revealed their position to fishermen.
Native tribes in the Amazon have a tradition to remove Arapaima scales and use them to make nail files for tribal attire. Native American legends claim that Arapaima is the name of the tribal chief of Amazon, Pirarucu. When the son was disobedient, God stroke him down to the very depths of the Amazon river. Stories were told that this fish is an evil-spirited animal that can pull men out of their boats and put them to death. The name ‘Arapaima’ is only used by English-speakers, but tribes refer to it as ‘Pirarucu’.
Arapaima has not been domesticated and it doesn’t make a good pet fish, due to its large-scale aquarium requirements. Arapaimas are kept in breeding camps and aquariums, but they’re not used for private aquarium owners. Arapaima requires a minimum 1000-gallon aquarium for a privately-ran breeding camp, and 10,000-gallon aquarium for public aquariums with multiple specimens. The presence of the fish might not comply with local laws of certain countries and states, and owners have to check about the legality of the fish well in advance.
The fish is acclimated to the vegetation-rich waters in the Amazon, and requires high-temperature waters year-round to survive. When they're kept in captivity they require vegetation on the ground to emulate their natural environment due of their tendency to hide in algae.
Recently more specimens were brought over to SE-Asia and they are now found in Malaysia and Thailand. The biggest breeding camp in the world is located in Thailand, and it was opened in 2018. The camp now exports Arapaimas internationally.
The fish was never an over-abundant fish in the Amazon basin, thus red alarms over its potential extinction were never raised. This prompted the IUCN (Red List of Threatened Species) to label it as "No Data", effectively meaning there is no way to measure whether the species is going extinct or sustaining its numbers.
Local governments who patrol the Amazon rivers ensure that no illegal fishing is done - the fish is under the protection of numerous South American governments.
Arapaima meat is classified as First-Class luxury meat: it's boneless, mild-tasting and odor-free. The color of the meat is white and it’s succulent. Arapaima meat has high market value and is desirable for restaurants all around the world. For consumption purposes, almost 50% of the fish is extracted in the Peruvian-Amazon basin, close to 40% of it is extracted in the Brazilian Amazon basin, and 10% in the areas of the Brazilian-Colombian border.
Arapaimas are very expensive, and rarely sold in large sizes. They are sold to private aquarium owners. Small 10cm/4” fish sell for $200, while slightly larger 20cm/8” ones sell for $400 on average. If a fish is 8”, it’s more likely to survive into adulthood and become large-sized. The fish is edible and contains medical properties. In local fishing communities along the Amazon basin, Arapaima fish is dried and served with guarana bark and water in order to kill intestinal worms.
The legal status for fishing differs by country, in Peru and Guyana the fish is unrestricted for recreational fishing. In Brazil it can only be fished in “catch and release” style or for eating by native tribes who use it for sustenance. Colombia only bans fishing between October 1st and March 15th when the Arapaimas natural breeding cycle ends. Arapaima is available in Whole Foods markets in the United States, where a farm-raised version of the fish is sold. In some states, such as Texas the species is banned for import –due to a fear that someone will release it in local Texas waters. Each state has different laws regarding the import of Arapaima fish.