Jacksonville Zoo and Gardens

Arapaima

Osteoglossidae

Osteoglossiformes

Actinopterygii

South America’s Amazon Basin and nearby lakes and swamps; In Guyana, arapaimas are found mainly in the Essequibo and Rupununi River systems in central areas.

Arapaima can reach lengths of more than 2 m (6.6 ft) and weigh approximately 100 kg (220 lbs.).  In some exceptional cases individuals reach more than 4.5 m (14.7 ft) long and weigh over 200 kg (440 lbs).  Arapaimas are grey in color with reddish-orange speckling near the posterior end. There are also two symmetrical fins on either side of the body at the posterior end.

15 to 20 years in captivity

Females are sexually mature by approximately 5 years.

In the wild, the arapaima eats fish, crustaceans, and other small animals.  In the Zoo, it is fed capelin and a scientifically developed, commercially available fish food.

IUCN – Data deficient; CITES – Appendix II

Due to the geographic range the arapaima inhabits, the animal’s life cycle is greatly affected by the seasonal flooding that occurs. The arapaima lays its eggs during the months of February, March, and April when the water levels are low or beginning to rise. They build a nest approximately 19.7 inches (50 cm) wide and nearly 6 inches (15 cm) deep, usually in muddy 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 male is a mouthbrooder, like its relative the Osteoglossum spp., meaning the young are protected in male’s mouth until they are older. The female arapaima helps to protect the male and the young by circling them and fending off potential predators.  The parental care includes helping to aerate the water for the offspring, which is a necessity for survival of the offspring in the oxygen-deficient waters of some habitats. Adults have the ability to exude a pheromone from their head to attract offspring and keep them in close proximity.

Because arapaimas must surface to breath air approximately every 10 to 20 minutes, they tend to remain near the water’s surface, where they hunt.  When they emerge to breathe they make a distinctive coughing noise.  It is this behavior that biologists and local fishermen use to assess the number of arapaimas in a given area.

This fish is an air-breather, using its swim bladder, which is rich in blood vessels and opens into the fish’s mouth, an advantage in oxygen-deprived water that is often found in the Amazon River. This fish is therefore able to survive in shallow waters with dissolved oxygen as low as 0.5 parts per million (ppm).

Its sheer size and bony armor provide defenses against most predators. Spectacled caiman and man prey on this species.

The arapaima is the largest freshwater fish in South America. As one of the most sought after food fish species in South America, it is often captured primarily by handheld nets for export, by spearfishing for local consumption, and, consequently, large arapaima of more than 6.6 feet (2 m) are seldom found in the wild today.

Fossils of arapaima or a very similar species have been found in the Miocene Villavieja Formation of Colombia.  A. gigas was first named by Georges Cuvier in 1817. This animal is often called a living fossil due to its archaic morphology.

The arapaima is also known as the paiche or the pirarucu. 

The tongue of this fish is thought to have medicinal qualities in South America. It is dried and combined with guarana bark, which is grated and mixed into water. Doses of this are given to kill intestinal worms. In addition, the arapaima’s bony tongue is often used to scrape cylinders of dried guarana, an ingredient in some beverages, and the bony scales are used as nail files.

In pop culture, the arapaima can be found:
• In the Nintendo Game Cube videogame Animal Crossing and subsequent sequels where the Arapaima is one of the rarest catches.
• In the PC game The Amazon Trail II the Arapaima (called Pirarucu in the game) sometimes appears while spearfishing it is one of the largest fish in the game, and only appears once in any one fishing session.
• In the Nokia NGage title Hooked On: Creatures of the Deep at the games Thailand resort Top CatsIn the Street Fighter II games, a large Arapaima is seen hanging in the background of Blanka’s stage in Brazil, along with an anaconda and the Amazon River.
• And, in the Petz games on Wii & PS2 Catz & Dogz 2, the Arapaima is found in Gongoro Peak.  There is also a Golden Arapaima, which is one of the rarest catches.

In 1976, the SUDEPE (Supertendencia do Desenvolvimento da Pesca) outlawed the killing of a pirarucu from October to March, during the low water season when this animal becomes so visible due to it’s sheer size. Also the SUDEPE declared that the pirarucu has to be at least one and a half meters in length before it can be killed.

While this giant fish’s habitat is relatively unmolested, overfishing has become a serious problem, and some South American authorities have attempted to enact protections.  The arapaima’s proximity to the water’s surface makes it vulnerable to human predators, who easily target them with harpoons.

In Guyana, arapaima populations have declined greatly over the last 30 years. It is one of the most sought after fish species in South America, especially Amazonia. The meat is boneless and constitutes up to 50% of the total body weight of the fish. Today, the scarcity of Arapaima is reason for concern for local Amerindians because the fish represented an important income source in a poverty stricken local economy. At the same time, conservation organizations are concerned because of the fundamental ecological role played by this top-of-the-food-web species has been lost from the globally important North Rupununi Wetlands and Iwokrama Forest.

An arapaima has been in the Jacksonville Zoo’s animal inventory since 2004.

2009