Intelligent and Playful
Dolphins are found worldwide, mostly in shallow seas, while five species of dolphins live in the world's rivers. Dolphins have a streamlined body that is adapted to swimming. Some dolphin species can swim up to 25 miles an hour for long periods which is more than three times faster than the best human swimmers. They are superb divers and have been known to dive as deep as 1,000 feet. They have excellent vision, a unique sense of hearing and poor sense of smell. Dolphins are considered to be playful animals as they are often seen leaping out of the water, spinning in the air and riding the waves before boats. They are highly intelligent and have large brains. Dolphins are good mimics of sound and clearly communicate with one another. The head of a dolphin has a round organ called the melon that is used for echolocation (like bats). This is a system that some animals use for navigating and finding prey. They do this by bouncing high-pitched sounds off of objects, and listening for the echoes.
There are forty species of dolphins and they vary greatly in size. The smallest of the dolphin species, Maui's dolphin, is around 4 feet long- or as tall as a 9 year old kid - and weighs around 90 lbs. The largest member of the dolphin family is the killer whale, which can grow to 30 feet long. Dolphins feed on fish and squid. They swallow fish whole, despite having 100 teeth in their mouths. The teeth are used to grasp prey. An adult dolphin may consume 30 pounds of fish or more in a single day.
Dolphins have few natural enemies- their greatest enemies are humans. They are threatened by hunting, accidental capture in fishing nets and pollution. Dolphins are protected in the United States under the 1972 Marine Mammal Protection Act and are the focus of many conservation and research organizations.