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Family: Arapaimidae

Common Name: Arapaima, Pirarucu (in Portugese) and Paiche (in Spanish).

Origin: South America, the Amazon Basin



The natural diet of the arapaima primarily consists of fish; various small animals and birds will also be captured and eaten.


Confirmed maximum recorded length is 390 cm (3.9 meters or 13 feet) with unconfirmed maximum of 450 cm (4.5 meters, close to 15 feet); maximum recorded weight 200 kg (441 pounds).

Water parameters

Soft to moderately hard, slightly acidic (pH 6 to 6.5), temperature 25-29C/77-84F.


This is certainly not a fish for the home aquarium; it may be seen at some public aquaria. Wild populations have declined significantly due to over fishing, as it is a popular and tasty food fish for the people who live in Amazonia. International trade in this fish is restricted. Since 2008, this species has been on the IUCN Red List of Threatened Species.

The fish has the ability to breathe air from the surface due to a lung-like lining of its throat, an advantage in oxygen-depleted water that is often found in the Amazon River and particularly during the dry season when the waters all but disappear in many places. This fish is therefore able to survive extensive drought periods by gulping air and burrowing in the mud or sand of the swamps.

Due to the geographic range that arapaima inhabits, the animal's life cycle is greatly affected by the seasonal flooding that occurs. Half of the year the arapaima experiences an abundance of water, which is a benefit to these aquatic organisms, however, the other half of the year the arapaima experiences drought conditions. The arapaima has adapted to this great fluctuation in many aspects of its life, including reproduction. The arapaima lays its eggs during the months of February, March, and April when the water levels are low. They build a nest approximately 50 cm wide and 15 cm deep, usually in sandy bottomed areas. As the water rises the eggs hatch and the offspring have the flood season to prosper, during the months of May to August. Therefore, the yearly spawning is regulated seasonally. The arapaima is a mouthbrooder.

This is the largest living freshwater fish in South America, and one of the largest in the world. A. gigas is the only species known to be alive in South America, but ichthyologists now believe there may have been five distinct South American species in the genus.

This species was first described as Sudis gigas in 1822 by H.R. Schinz; a conspecific was described by G. Cuvier in 1829 and given the same name. In 1968, J. Daget moved it into the genus Clupisudis, where it remained until 1986 when Ortega and Vari moved it into the genus Arapaima that had been erected by J. Muller in 1843. The name is from the tupí-guaraní, arapaima [source: Fishbase].

The family Arapaimidae is composed of only two species, the Neotropical Arapaima gigas, and the African bonytongue, Heterotis niloticus; these two had in the past often been included within the family Osteoglossidae. The name Heterotidae has been used for this family, but the name Arapaimidae is older and, thus, is the correct name [source: Fishbase].

This family is one of seven in the Order Osteoglossiformes. This name derives from the Greek osteon [= bone] and glossa [= tongue] plus the Latin forma [= shape], and in English these fishes are referred to as the bony tongues. Other living species in this order include the elephant noses, arowana, pantodon (African Butterfly Fish) and the knifefishes. This is a very primitive order, with fossil records as far back as the late Jurassic period (roughly 161 to 145 million years ago). To put this into perspective, this was the period when the supercontinent Pangaea broke up into the two supercontinents Laurasia and Gondwana, which in time further divided and reformed into the seven continents as we know them today.

The first photo below depicts this fish in its habitat, filmed by the BBC. The second photo shows an A. gigas caught in Bungsamran Lake, Thailand, where the species was introduced for fishing.

Contributing Members

The following members have contributed to this profile: Byron


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