The Arapaima fish is also known as the Pirarucu, and is one of the biggest freshwater fish species in the world. Its scientific name is Arapaima gigas. This fish can only be found wild in the Amazon River Basin in South America. It can reach a length of 450 centimeters (177.17 inches) and weigh up to 200 kilograms (440 lbs). The Arapaima is grey and decorated with an orange speckling at the posterior end. The scales can grow up to six centimeters long on the largest Arapaima specimens. You will find two symmetrical fins on the body, located at the posterior end.
The Arapaima can be kept in aquariums, but you must of course be prepared to provide your Arapaima with larger and larger aquariums as it grows. A 450 centimeter long Arapaima is of course very impractical to keep for most aquarists. Since the Arapaima is near extinct in some parts of South America, you should choose your specimen carefully. Purchase a captive breed Arapaima or make sure that is has been caught in an area where it is not endangered.
The Arapaima is a very popular food fish in South America and it is also admired among sport fishers. More than 50 percent of the total body weight of this fish is made up by meat, and the meat is boneless, a fact which makes it even more popular as food. The bony tongue is used to prepare cylinders of dried guarana, while the scales are sold as nail files. (Guarana is an ingredient used in a South American beverage.) A majority of the caught Arapaima fishes are sold and consumed in Brazil. Arapaima harvesting is today forbidden in many regions, e.g. Guyana, but the illegal fishing still continues.
Over fishing has made it hard to find large Arapaima specimens. Once upon a time, there were a lot of Arapaima fishes weighing over 150 kilograms and measuring more than 3 meters in length. More than 30 years of over fishing have now drastically reduced the amount of large Arapaima fishes in South America, and has had a severe effect on the entire Arapaima population as well. The Arapaima fish is usually netted or harpooned.
The Arapaima is a predatory fish that eats fish, birds and any other animal that it can catch. The major part of its diet consists of fish, but since it is a large opportunistic hunter it will happily gulp down other animals as well. Arapaimas prefer to hunt close to the surface since they need to breathe oxygen from the air. This does however not prevent the Arapaima from occasionally diving very far down. The fact that this fish needs to breathe air from the atmosphere every 10-20 minutes must of course be taken into consideration if you intend to keep an Arapaima in captivity. The aquarium must be arranged in a way that makes access to fresh air possible.
Arapaima is found in various habitats in the Amazon River Basin which means that you can have some freedom when you decorate its aquarium. You will find Arapaima in the Amazon River, in the tributaries and in the floodplain lakes. It lives in white water as well as clear water, and the fact that it breaths oxygen from the atmosphere makes it possible for this fish to live in oxygen depleted swampy waters as well.
The Arapaima is an egg-laying mouth-brooding species that tend to its eggs as well as its larvae. Since Arapaima fish sometimes inhabit oxygen depleted waters, they will aerate the water to make sure that the eggs get enough oxygen. Adult fish can communicate with their offspring by exuding a special pheromone from the head. The pheromone makes the larvae stay close to their parents where they can be protected from predators.
The reproductive cycle of Arapaima fish depend on the seasons, and the female will lay eggs in February, March or April. During this period, the water levels in the Amazon River Basin are very low. The eggs are placed in a nest that has been built by the parents at the bottom. This nest is usually around 50 centimeters in diameter and 15 centimeters deep. When the eggs hatch, the flooding season is well on its way in the Amazon River Basin and the offspring can feast on an abundance of small aquatic organisms.
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