While the specific origin of the Indian Ocean's name is not commonly known, it is generally believed to have been named due to its proximity to India. During the 15th century, when sailing ships were used to transport goods around the known world, the Indian Ocean was the main trade route between Europe and the Far East.
Vasco da Gama, a Portuguese sailor, is considered to have been the first European to enter the Indian Ocean, via the Cape of Good Hope, on his way to India. This ocean, comprising about one-fifth of the Earth's total ocean water, is the smallest of the major oceans at about 28,360,000 square miles.
The Indian Ocean is also the youngest of the world's oceans. When the supercontinent Gondwana began to break up approximately 150 million years ago, the Indian Ocean began to form. It did not achieve its current position and size, however, until about 36 million years ago.
The Indian Ocean is home to a variety of plant and marine life, including seals, whales and tuna. However, because of the warmer temperatures of this ocean, phytoplankton exist only in smaller quantities, thereby limiting the amount of fish and other marine species much more than in the other oceans.