Wonder River Amazon


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The greatest river of South America, the Amazon is also the world’s largest river in water volume and the area of its drainage basin. Together with its tributaries the river drains an area of 2,722,000 square miles (7,050,000 square kilometers)—roughly one third of the continent. It empties into the Atlantic Ocean at a rate of about 58 billion gallons (220,000 cubic meters) per second.

The Amazon varies in width from 4 to 6 miles (6 to 10 kilometers); its mouth is more than 150 miles (240 kilometers) wide. The largest oceangoing steamers can ascend the river 1,000 miles to Manaus, a Brazilian inland port.
For most of its course the river flows just south of the Equator, and so the Amazonian climate is hot and humid. Annual rainfall amounts to about 50 inches (130 centimeters), while the average temperature over a year is about 85° F (30° C). Most of the Amazon Basin is a lowland forest of hardwoods and palms. The northeastern portion has extensive savannas, or grasslands, with occasional trees and shrubs.

Plants and Animals

The remarkably rich and diverse Amazon Basin plant and animal life is a resource of world importance. Of all the species of plants in the world, almost three fourths, many of which are still unidentified, live in the Amazon Basin. The Amazon has often been described as a vast sea of fresh water that supports about 1,500 to 2,000 species of fish, including catfish, electric eels, and piranhas. The basin also has an immense variety of insect, bird, reptile, and mammal life.

The vegetation of the Amazon jungle grows rapidly, soon covering cleared areas unless it is cut back constantly. Again and again the jungle has defeated settlement efforts. At the same time, conservationists are concerned about the overcutting of valuable plants such as hardwood trees and also the destruction of rare plant species when the jungle is burned over for clearing. The many Amazonian plants are a valuable source for development of new hybrids.

Mammals include the capybara, a rodent weighing up to 110 pounds (50 kilograms) whose flesh is eaten; the tapir, an edible kind of pig; the nutria, a tropical otter whose pelt is traded; the great anteater; and many kinds of monkeys. Markets along the river sell a variety of fish, including the pirarucu, which weighs up to 325 pounds (150 kilograms), and the giant catfish. Silver carp, neon tetras, and the flesh-eating piranhas are shipped to tropical fish stores throughout the world. The electric eel is a dangerous fish capable of discharging up to 500 volts.

The wide range of vividly colored Amazonian birds includes hummingbirds, toucans, and parrots. Among the reptiles are the anaconda, a huge snake that crushes its victims; the poisonous coral snake; and alligators. Giant butterflies are among the most spectacular of the insects.