The River Amazon has thousands of tributaries that flow through the rainforest. Some of these channels are wide and deep, while others are narrow, shallow and full of fallen leaves, branches and winding tree roots. The river teems with fish, including predators such as the notorious piranha, the electric eel and the arowana, which will often leap out of the water to snatch insects or even birds. By night, various forest animals come to the river banks to drink. Tapirs, peccaries and capybaras are wary of dangerous predators, such as jaguars.

Floods

During the Amazon rainy season (from December to May), vast areas of the forest floor flood, and fish swim among the tree trunks. River animals like the giant otter, the caiman or the Amazon dolphin, go off in pursuit of them. Some animals, such as the capybara, anaconda or jaguar, are good swimmers and are easily able to negotiate the floodplains. Others, such as monkeys, iguanas and anteaters, take to the trees during the floods.

Fish

The largest of all Amazon fish, the pirarucu (or arapaima) grows to 3 metres (10 feet) or more in length. It prefers shallow, swampy water to spawn. It has a swim bladder, a kind of “lung” which it uses to breathe air when its head is above water.

The piranha is armed with razor-sharp teeth. Schools of 20 or more piranhas will, on detecting blood in the water, set about an injured animal, reducing anything the size of a pig to a mere skeleton in a very short time. Normally, the piranha feeds on small fish and fruit.

The caiman, a type of crocodile, lurks in shallow water with just its eyes and nostrils showing. It usually feeds on fish but is also capable of attacking animals such as tapirs and capybaras. When they come to the water to drink, it seizes them in its teeth and drags them under water.

The matamata, a river turtle, lurks on the riverbed waiting for fish to approach. The flaps of skin on its neck attract the fish’s curiosity—and also help it to sense approaching prey. The matamata then suddenly thrusts out its neck and grabs it.
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Iguanas are kinds of lizards. The green iguana has a crest of comb-like spikes running down its back. If danger threatens, it will simply drop out of the trees into the water below. The green anole, another kind of iguana, has long toe pads to help it grip to tree trunks. The male’s red throat flap is used in displays to attract females.

Amphibians

Some tree frogs climb high up into the trees. They carry their tadpoles on their backs, searching out hollows where water has collected. Here the tadpoles develop into adults.

The Suriname toad also carries its young on its back—in special pockets. This unusual toad has a flat, square body, webbed hind feet and star-shaped fingertips.