Arapaima gigas, one of the largest freshwater fish

When it comes to giants of the aquatic world, we often think of sea creatures like sharks, dolphins, or whales. However, even in freshwater rivers, you would be amazed by the immense sizes of certain fish species.

One such astonishing giant is the Arapaima, also known as the “freshwater monster” of the Amazon region. Discovered by Swiss biologist Louis Agassiz in 1829, the Arapaima (also called the “giant pirarucu” or “pirarucu”) is found in the tropical regions of South America and is considered one of the largest freshwater fish species in the world.

Some individuals of this species can reach extraordinary sizes, weighing up to 200kg and measuring 3 meters in length. There have been documented cases of Arapaima specimens measuring 4 meters in length and weighing 300kg.

Because of this, many avid anglers often whisper to each other that when hunting this fish, one should avoid startling them. Only when you see them surfacing and swimming gently should you attempt to catch them. Despite their massive size, Arapaima fish are quite timid. When startled, they thrash around and forcefully expel water as a way to showcase their appearance.

One distinctive feature of the Arapaima is its ability to breathe air by gulping it from the surface of the water. In addition to gills, this fish “extracts” oxygen from the air using a labyrinth organ in its throat, which functions like lungs in terrestrial animals.

Young Arapaima have silver-gray scales, a round and elongated body shape, and their heads resemble those of pike. Adult Arapaima have a darker, gray-brown coloration with a metallic sheen. The scales on their dorsal fin, tail fin, and anal fin exhibit red or orange spots, making them even more remarkable.

Arapaima can survive during dry seasons or in oxygen-deprived conditions in the flooded areas of the Amazon by burying themselves in the muddy sand of swamps and breathing through their mouths. However, this air-breathing activity needs to occur every 5 to 15 minutes.

Another notable characteristic of the Arapaima is its ability to breathe by gulping air from the water’s surface.

Their daily diet consists of fish, crustaceans, and small creatures near the shores. However, occasionally, Arapaima demonstrate their strength by leaping several meters above the water to catch prey such as snakes or birds.