Amazon River is the largest river on Earth in terms of water volume and width. The river and its basin are home to many unique species of animals, trees and plants.

The river originates from the Andes mountain range of Peru and travels through Ecuador, Colombia, Venezuela, Bolivia and Brazil in South America before emptying into the Atlantic Ocean.

Amazon River is the second longest river in the world. At about 4,000 miles (6,437 km) long, Amazon is slightly shorter than the Nile River, which runs for around 4,258 miles or 6,853 km.

At some places, the width of the river reaches nearly 30 miles or 48 kms. The river releases around 200,000 litres of freshwater into the ocean every second.

Here are some of the lesser known facts about Amazon River:

Once flowed in the opposite direction

Amazon River once flowed in the opposite direction. Around 100 million years ago, the river flowed towards the Pacific Ocean, in the opposite direction it flows today. Where the Amazon River's mouth sits today, there was once a highland that allowed for this westerly flow. The rise of the Andes Mountains in the west forced the Amazon River to reverse course.

Affects sea level in the Caribbean

The Amazon River releases so much freshwater into the Atlantic Ocean, it alters sea level in the Caribbean. As freshwater leaves the mouth of the Amazon, it gets picked up by the Caribbean Current, which carries the water to the Caribbean islands. On average, models predict the Amazon River alone causes sea levels around the Caribbean to be around 3-cm higher than they would be without the Amazon's freshwater contributions.

Home to pink river dolphin

The Amazon River Dolphin, also known as the pink river dolphin or boto, is one of just four species of ‘true’ river dolphins. Unlike their ocean-dwelling counterparts, river dolphins live exclusively in freshwater habitats. Based on a fossilized dolphin discovered in Peru's Pisco Basin, the Amazon River Dolphin is estimated to have evolved about 18 million year ago.

Dorado catfish also lives in Amazon

The Dorado catfish is one of six species of ‘goliath’ catfish found in the Amazon River. Like the capaz and mota catfishes, the goliath catfishes are commercially important species, with the Dorado catfish being perhaps the most important of all of the Amazon's catfish. The Dorado catfish can grow up to six feet in length and migrates over 7,200 miles to complete its life cycle.

Named after Greek myth

The Amazon River and the Amazon Rainforest were named by Francisco de Orellana, the first European explorer to reach the area, after he encountered the indigenous Pira-tapuya people. In a battle against de Orellana and his men, Pira-tapuya men and women fought alongside one another. According to Greek mythology, the ‘Amazons’ were a group of nomadic female warriors that roamed around the Black Sea. Based on this mythology, it is thought that de Orellana named the river ‘the Amazon’ after his battle with the Pira-tapuyas, likening the women of the Pira-tapuya to the Amazons of Greek mythology.

Amazon has over 100 dams

According to a study conducted in 2018, the Amazon River's Andean headwaters have 142 dams, with an additional 160 dams proposed for construction. These dams provide electricity in the form of hydropower but hurt the ecology of the Amazon River system. Fishermen in Brazil's portion of the Amazon River, the Madeira River, already report negative effects on the system's fish, which scientists attribute to the installation of hydroelectric dams.

No bridges

All 10 million people who live on the banks of the Amazon River can only cross the freshwater flow by boat. The lack of bridges over the river is due to seasonal changes in the riverbed. During the rainy season, the Amazon River can rise over 30 feet, tripling the width of the River in some places. The Amazon's soft river banks erode as with the seasonal inundation of rainwater, making previously sturdy areas into unstable floodplains. There are also few roads connecting to the Amazon River, with the River itself used for most people's transportation needs.