Seals are any of the species of aquatic mammals belonging to the taxonomic Family Phocidae. They commonly known for their pelts for their performances in circuses and aquariums. Besides the fact that they are on the verge of being endangered. They live in the ocean and on beaches in Antarctica, up and down the western coast of the United States, Canada, Norway and Sweden.
Every seal has thick, short hairs that cover its blubber, thus keeping the seal from freezing in extremely cold temperatures. They have three total flippers: one in the back called the hind flipper, and two in the front that are hairy fore- flippers with blunt claws attached. They have closeable ears, two large eyes with photoreceptor cells, extremely sensitive whiskers, two nostrils and several specially designed teeth that can filter krill, and a very thick neck.
The shape, color, and size vary with the species. Leopard seals have the distinct leopard-spotted pattern on their fur, and are know to kill and eat their own young. Typically, females are lighter in color and have more grays and browns with black spots. Males are bigger and bulkier. Crabeater seals weigh up to 440 lbs and grow up to 8.2ft long. While Weddell seals weigh up to 1320 lbs and grow to 9.84ft long.
All have a circulatory, respiratory, digestive, skeletal, reproduction and nervous systems. Seals have 15 pairs of flexible ribs that can withstand the water pressure they dive to, to get food and play.
Seals reproduce sexually; they usually mate in April and give birth nine to ten months later, depending on the species.They typically give birth during the spring or summer. Some females will give birth in groups and then go and mate with another male, and others will give birth by themselves.
Male seals become sexually mature at the age of six to 10 years old and a female becomes sexually mature at five to six years of age. 
Most seals eat fish, like salmon, also, shellfish, such as mussels, clams, oysters, crabs. Leopard Seals in Antarctica eat Adelie penguins.. The Ross seal primarily feed on squid and fish,  On the other end of the food chain, Seals are prey for Orcas, Greenland Sharks, and Polar Bears.
Seal hunting, or "sealing" is a very popular sport. In Canada, Greenland, Norway, and Russia, many people have made sealing their profession. The traditional way of killing a seal in seal hunting is by clubbing the seal to death, dropping pieces of ice on their heads, or shooting them.
In the northern Atlantic, during the 1970's, the Harp seal population decreased by two million, forcing government officials to put stronger regulations on sealing. In 2007, 234,000 seals were killed during the seal hunting season. That count was down 354,000 seals from 2006. Now in Canada, it is illegal to hunt baby seals (known as pups.) As soon as the pup molts at 12-14 days of age, they are then called ragged- jackets and are fair game.
In 2006, ninety-eight percent of Canada's Harp Seals pups under the age of three months were clubbed . A group of Canadian veterinarians found that forty-two percent of seal injures were due to sealers skinning the seals while still conscious.
The main reason commercial sealing is so popular is because seal pelts are greatly prized in high fashion lines; Eskimos and other natives also regularly eat seal meat. Nevertheless, sealing is a cruel and unusual sport to enjoy. 
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