The Sea Turtles

Sea turtles have existed for more than 150 million years and have survived all the changes our planet has gone through. They were originally land animals, and as they took to the sea, evolution made them different from the other reptiles. As a result, the number of vertebrae decreased, and those remaining fused with the ribs, forming a tough but light shell, or carapace. They lost their teeth, acquired a type of bill, and their paws became flippers. All this in order to adapt to life in the sea.

There are seven species of sea turtles, grouped in two families: the Dermochelydae and the Chelonidae. Five of these seven species may be found in Brazil: the Loggerhead (Caretta caretta), the Hawksbill (Eretmochelys imbricata), the Green turtle (Chelonia mydas), the Olive Ridley (Lepidochelys olivacea) and the Leatherback (Dermochelys coriacea).

Sea turtles are reptiles, and as such, they have dry skin covered with scales, breathe through lungs, and their body temperature is regulated by the temperature of the environment. They belong to the same order as fresh water and land turtles, such as the tortoise, but they are much bigger, and may weigh up to 2,000 pounds (900 kilos). However, instead of paws, they have flippers and live in the sea all the time. Usually, only the females leave the water, briefly, to lay eggs. On land they are very slow and become vulnerable; in the sea, they are agile and quick-moving.

Sea turtles' bodies are covered by a shell, made of horny, bone-like plates, which protect them from predators and improve their hydrodynamics, making it easier for them to move in the water. Even though they have lungs, they are capable of staying underwater for a few hours, holding their breath. To that end, their organisms function slowly, their hearts beat at a slower rate, a phenomenon called bradycardia, in which the oxygen supply is aided by a type of supplementary breathing, carried out by the pharynx and cloaca, which extract oxygen from the water.

Species in Brazil

Take a comparative look
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Where are the turtles in Brazil?
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Protected Areas
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