There are thought to more than 30 different species of seal found in the world's cooler waters from the smallest species of seal, the Caspian seal to the Elephant seal which is the largest species of seal. Other seal species include the grey seal and the leopard seal which is known for it's highly predatory and aggressive behaviour Seals are closely related to sea lions and also walruses
Surprisingly, seals only spend around half of their time in water as the other half is spent on land. After a gestation period of between 11 months and a year, baby seals (known as seal pups) are born on land. Seal pups develop very quickly and some baby seals are often able to swim within a few hours of birth. Seal pups are born during the spring and summer months when temperatures are warmer and there is plenty of food.
Generally, seals live until they are about 20 years old but some species of seal live for a shorter period of time, where other seal species can live until they are nearly 40. Due to the fact that seals are a targeted food source for many species of animal, some seals in the wild will only live for a very short period of time.