The endangered sea turtle’s body is designed for ocean life. Their shells are lighter and more streamlined than those of their cousin the land turtle. Sea turtle’s front and rear “legs” have evolved into flippers making them able to glide through the water efficiently and effortlessly swimmers. They are able of swim long distances in a relatively short period of time. Sea turtles have been known to move through the water as fast as 35 mph.
Because they are not fish, but reptiles when active, sea turtles must swim to the surface every few minutes to breathe. Although during rest or periods of sleep adult sea turtles can remain underwater for more than 2 hours without breathing.
Why are they able to stay under water so long?
Sea turtles blood can carry higher concentrations of carbon dioxide than most other air-breathing animals. This allows their blood to use its oxygen supply more efficiently so their muscles and blood are able to store oxygen in large quantities. Since adult sea turtles usually sleep at night under water, young sea turtles need to sleep afloat at the water’s surface, because their blood has not developed this oxygen concentrating ability. This makes them more vunerable to prey.
In addition to solving the problems of swimming and breathing, sea turtles have also come up with an ingenious way to rid their bodies of the salts they accumulate from the seawater in which they live. Just behind each eye is a salt gland. The salt glands help sea turtles to maintain a healthy water balance by shedding large “tears” of excess salt. If a sea turtle appears to be “crying” it is usually not cause for alarm, as the turtles are merely keeping their physiology in check. It is not because they are upset or sad.
The shape of the shell gives helpful clues to how the turtle lives. Most tortoises have a large dome-shaped shell that makes it difficult for predators to crush the shell between their jaws. One of the few exceptions is the African pancake tortoise, which has a flat, flexible shell that allows it to hide in rock crevices. Most aquatic turtles have flat, streamlined shells which aid in swimming and diving. American snapping turtles and musk turtles have small, cross-shaped plastrons that give them more efficient leg movement for walking along the bottom of ponds and streams.
All turtles need our protection, please keep the waterways and ocean free of litter will help save many turtles and tortoises from extinction.
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