Antarctica is roughly 98 percent ice, according to the Central Intelligence Agency. Despite its lack of natural resources such as soil and trees, Antarctica is surprisingly inhabited with numerous types of animals, including seals. The harsh Antarctic environment demanded that seals develop specific adaptations to successfully survive and reproduce.
Seals have large eyes with a spherical lens to see underwater where light is scarce -- a hunting adaptation that is essential for their survival. To withstand the harsh rays of the sun reflecting off of the water and ice, seals in Antarctica developed a mobile pupil as well as a special membrane that covers their eyes when swimming underwater. Without their highly adapted eyes, seals would not be able to navigate waters while hunting or escaping from predators.
Hunting and Eating
Hunting in Antarctica requires speed and agility, which seals don't have on land. But underwater, seals are agile swimmers thanks to their muscular fore and hind flippers that propel them through water. Seals adapted to eating in Antarctica by developing two special types of teeth, according to the Department of Education in Tasmania. One type, their molars, evolved to be cusp-shaped to easily filter krill, a type of small crustacean found at the bottom of the food chain. Additionally, seals' teeth are very sharp to catch and cut up fish.
Diving and Swimming
Seals in Antarctica adapted the ability to hold their breath underwater for approximately 15 minutes, according to the University of Wisconsin-La Crosse. Seals such as the Weddell seal carry almost two times the amount of oxygen that humans carry, enabling them to stay underwater for long periods of time. Seals also use their whiskers when swimming to search for prey. While diving in search of food, seals are able to blow bubbles up under broken ice to scare out fish.
Body Temperature Regulation
Seals regulate their body temperature in several ways. When cold, seals rely on their thick layer of blubber, or fat, to keep their organs insulated. Younger seals' skin is kept warm by a layer of water-repellent fur, which remains until the seals grow the fat layer. Damaged skin loses heat quickly, and adult seals easily damage their skin from constantly swimming and crossing over ice. Since their skin is an important asset in staying warm, adult seals shed their skin every year and grow new skin to prevent hypothermia.
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