Seals are semi-aquatic marine creatures that are carnivorous in nature. They use their fins as feet and spend most of their time in water. There are about 33 known species of seals. The super family Pinniped is divided into 3 different subfamilies based on the characteristics of the members. These families include the Odobenidae, Otariidae, and Phocidae. They have sleek bodies that are barrel-shaped. The size varies with species. Seals are highly intelligent marine creatures and aggressive too. They will attack humans on getting too close to their home or young ones. They love basking in the sun and spending long hours on rocks. When underwater, they are agile hunters and fine swimmers. They undergo molting that is, shedding of skin. This process takes about 6 weeks to complete. During this time, they tend to become very irritable and make a lot of noise because of the high levels of hormones in their body. When molting, they do not eat anything. The blubber in their body helps them survive these long weeks without food. Odobenidae The Odobenidae family has the walrus as the only surviving member. The long tusks are hard to miss when trying to spot one. They feed on clams and mollusks. Weighing over 4, 400 lbs, they are found exclusively on the cold lands of the Arctic. Otariidae The Otariidae family consists of the Eared seals as the members. They are also known as the walking seals as they move on all fours when on land. They have external ears that helps differentiate them from true seals. These social creatures are very noisy. They are commonly known as the Sea Lions and the Fur seals. Phocidae True seals or the 'earless seals' are the most commonly found members of Phocidae family. These seals do not have an external ear and are far better swimmers than the eared seals. They are, however, a bit clumsy on land and use only their front flippers for walking. They do not vocalize a lot and tend to grunt or slap the water to communicate with each other. The leopard seal is the second largest seal of all the species, inhabiting the cold regions of Antarctic ocean. The leopard seal is the most aggressive of all seal types. They live in small groups as compared to other seals. It is not uncommon to see leopard seals living in pairs. They eat krill, fish, and other small marine creatures. Their favorite food is a freshly caught penguin. The average life span of a leopard seal in the wild is about 26 years. Seals with little brown or black fur are harp seals. They look like polar bear pups when young. They live around the coasts of Atlantic and Arctic ocean. They are about 5½ feet in length and weigh about 400 lbs. Their diet consists of small fish and invertebrates. The average life span of harp seal in the wild is about 30 years. Smaller in size compared to other seals, the harbor seals are just about 6 feet in length. They have a distinctive pattern of spots on their body and 'V' shaped nostrils that are not found in any other species. They are found along the Arctic coastline, Atlantic Ocean, Pacific Ocean, and the Baltic Sea. Their diet consists of octopus, squid, cod, herring, salmon, and walleye. The life span of female harbor seals is about 30 to 35 years and males is about 20 to 25 years in the wild. The gray seal is a medium-sized seal that reaches about 10 feet in length. Their nostrils are placed wide apart on their face and have a brown to dark gray color. Their diet consists of different types of fish. They live for about 30 years in the wild and 40 years in captivity. The male Northern Elephant seals have a snout on their face like an elephant. The males are large in size and grow about 14 feet in length. The females are shorter than males, yet reach a length of about 11 feet. They are light gray to dark black in color. They usually hunt at night and eat a lot of fish and marine animals. The largest seals in the world are the Southern Elephant seals. They too have a snout or trunk like projection on their mouth that makes them look like elephants. This species is characterized by a large head. They are known to make deep loud sounds that seem like roars. These sounds are particularly made by males around breeding season. They feed on squid, fish, and sometimes penguins too. These seals are able to live under water for about 2 hours by lowering their heart rate to about 1 beat per minute. They are about 10 feet in length and can weigh about 1,000 pounds. They mostly inhabit an area called the McMurdo Sound, that is about 800 miles away from South Pole. The males are very vocal and will continuously make sounds to claim their territory. Also, they are not very aggressive and very calm in nature when compared to other types. The Hawaiian monk seals are found inhabiting the waters of Hawaii. The females are about 8 feet in length and males are about 7 feet in length. They are more of solitary animals and are found living alone or in small groups. These types of seals are very good swimmers and have a great eyesight. Thus, they are great hunters and have no trouble finding food in water. These seals are not very noisy and spend their time quietly basking in the sun. The live for about 25 years in the wild. The Antarctic fur seals are the types of seals that have visible external ears. These seals also have long whiskers and waterproof fur on the body. They can grow about 6 feet in length. They live on land as well as in water. They feed on fish, squid, and krill. The life span of a female Antarctic fur seal is about 25 years and that of the male about 15 years. The Galapagos fur seals are found inhabiting the Galápagos Islands around Ecuador. The color of these seals is dark brown to light gray. They feed at night and can spend long hours in search of food. They spend 6 days in water and then one whole day on land. The average life span of these seals is about 20 years. The Northern Fur seals are found in the northern region of Pacific ocean, Bering sea, and the Sea of Okhotsk. These seals have small-sized heads and a curved mouth. Their nose is very small and sport very thick fur. They eat any type of fish they are lucky to find. They are not deep divers and spend most of their time on the shoreline. Most of these seals are placed under the endangered animals list due to over-hunting and loss of natural habitat. Global warming is adding to their woes. Conservation steps will help prevent their extinction.