Arapaima

Care at a glance

Overview

This fish is not suitable for a normal home aquarium: it reaches two to three metres and needs a pond or public-scale system of many thousands of litres, so plan on 40000 litres or more. Keep the water warm at 25 to 30 C and pH 6.0 to 7.0 with heavy filtration and constant surface access for air breathing. It will eat any tankmate it can swallow. Only experienced keepers with the right facilities should attempt one.

In the wild

The arapaima is one of the largest freshwater fish on Earth, a torpedo-shaped air-breather with a broad head and red-flecked rear scales. It rises to the surface every few minutes to gulp air from a modified swim bladder that works like a lung. In the wild it grows quickly and preys on fish and anything else it can engulf.

Good to know

Arapaima gigas belongs to the family Arapaimidae and can exceed 250 cm and 200 kg, with historical reports up to around 450 cm. It is an obligate air-breather that will drown if denied surface access. The tongue is bony and toothed, and dried tongues have long been used as tools.

Did you know

Arapaima can grow from a hatchling to well over a metre in their first year, one of the fastest growth rates of any freshwater fish.

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