The Arapaima Is Built Wrong

The arapaima is a large freshwater fish native to the Amazon and Essequibo basins. Portuguese call it pirarucu, meaning red fish.

Arapaima reach 3 m in length and weigh up to 200 kg. A club saves on bait.

Arapaima became available for sale in American grocery stores.

Arapaima scales have a hard outer layer over collagen fibres arranged like plywood. This armor flexes while protecting the fish.

An enlarged swim bladder works as a lung, letting arapaima breathe air. They survive in water with 0.5 ppm oxygen.

Male arapaima keep young in their mouths. Females circle nearby, fending off potential predators.

Some 23-million-year-old arapaima fossils were found in Colombia. Museum specimens exist in France, England, and Brazil today.