Arapaima

Fascinating facts about the Arapaima

• A arapaima can grow to 3 metres long — as tall as a basketball hoop — making it one of the largest freshwater fish on Earth. In the Amazon's murky water, that size is an advantage: it allows them to hunt fish and crustaceans in the dark by sensing the slightest vibrations with a lateral line that runs the full length of their body. By the time a prey fish realizes it's been detected, the arapaima's vacuum-like gulp has already sealed its fate.
• Unlike most fish, arapaimas must breathe air or they will drown. Every 5 to 10 minutes they rise to the water's surface and gulp oxygen directly into a lung-like organ that lines their swim bladder. Indigenous Amazonian peoples have hunted them for centuries by timing the rhythm of these breaths — knowing exactly where the fish will surface, they can spear or shoot it with precision. This adaptation makes them predictable to human hunters, and locally vulnerable despite their global status.
• A arapaima's scales are almost impenetrable — composed of a composite material of bone and enamel that stays supple even in the oxygen-poor, acidic water where piranhas and caimans hunt. When a predator bites down, the scales don't shatter like rigid armour; instead they flex and absorb the force, distributing the pressure across the fish's entire body. Archaeological evidence shows indigenous people used arapaima scales as tools and weapons because nothing freshwater could pierce them.
• During the wet season, arapaimas form pair bonds and guard their eggs in floating nests made of vegetation. Both parents defend the clutch ferociously — a behaviour rarely seen in fish. The male and female coordinate their movements, taking turns at the nest entrance. This level of parental care is usually reserved for animals with long lifespans or high investment in few offspring, yet arapaimas practice it despite living in water filled with predators that would love to raid an unguarded nest.
• An arapaima can live over 50 years in the wild, making it one of the longest-lived freshwater fish. This extended lifespan means a single female may produce millions of eggs across her lifetime, yet the species' population can collapse quickly if fishing pressure is too intense — she may never reach reproductive age before being caught. The fish's combination of slow growth, high commercial value, and predictable breathing makes it especially vulnerable to overfishing, which is why Indigenous co-management of arapaima populations in protected areas has become critical to their survival.

At a glance

About the Arapaima

In the murky depths of the Amazonian waters, the arapaima glides effortlessly, its sleek, armored body undulating as it navigates the sun-dappled shadows. With a gentle flick of its tail, this ancient giant can leap from the water's surface, breaching the air with a sudden, startling explosiveness that belies its otherwise languid demeanor. As it breaks the surface, the arapaima's scales shimmer like molten gold, casting a fleeting glimpse of beauty in the dappled light of the rainforest.

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