5 Fun Facts You Never Knew About The Arapaima

Unless you watch a lot of the Animal Planet show “River Monsters” or are a frequent visitor to your local aquarium, you might not have heard of the arapaima. Native to South America’s Amazon River basin, the arapaima is one of the world’s largest freshwater fish and it’s been relatively unchanged for millions of years. Here are 5 fun facts you never knew about the arapaima.

#1 – They can be more than 8 feet long

While they are typically closer to 6 or 7 feet long, they can reach lengths of 8 feet or more. The longest arapaima on record was 15 feet long! They typically weigh around 200 pounds but have been recorded as heavy as 440 pounds.

#2 –  They breathe air

image source: Cyndy Sims Parr via flickr

They have a modified swim bladder that acts as a primitive lung. They need to come to the surface of the water to breathe every 10 to 20 minutes. On the flip side, they can survive out of the water for up to 24 hours. The ability to breathe air allows the arapaima to thrive in oxygen-poor waters, such as remote areas where floodwaters contain a lot of decaying vegetation.

#3 – Males incubate the eggs in their mouths

image source: Alice Chodura via flickr

While the eggs are typically laid in a nest, the slightest hint of danger will find the male hiding the eggs in his mouth or relocating them to a safer area to avoid predators. The female will swim around guarding the nest and the male with the eggs in his mouth and fending off predators.

#4 – Their lives revolve around seasonal flooding

image source: Evan Howard via flickr

Arapaima lay their eggs during the dry season from February to April. The eggs hatch at the beginning of the wet season, between October and November, when there is plenty of food. The flood season spreads the arapaima far and wide, where they then may get trapped in smaller pools of water as the floodwaters recede.

#5 – They create a vacuum when they open their mouth

Image source: Jeff Kubina via flickr

Opening their large mouths creates a vacuum that sucks their prey in. While they usually eat fish, they will eat just about anything that comes in the water, including fruits, seeds, insects, birds, and mammals.


(H/T: National Geographic, National Zoo, Wikipedia)