The ancestors of sea lions lived on land and evolved into animals living in water. Seals are close relatives of sea lions. Mature male sea lions have manes similar to lion hair on their necks and backs, so people call them sea lions. Sea lion is a kind of pteropod with external ear. Many of its organs have evolved, such as hands and feet, and evolved into fins to adapt to life in water. Sea lions have a strong swimming ability and can easily fish in the water. Sea lions have a very open view of marriage. A male sea lion can marry about ten female sea lions. Male sea lions use smells and calls to summon female sea lions and baby sea lions. Between fish and penguins, it prefers to eat penguins.