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common dolphin

Habitat and Distribution | Physical Appearance | Behavior | Breeding and Reproduction | Diet | Fun Facts

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Habitat and Distribution

There are two species of common dolphins - the long-beaked common dolphin (scientific name: Delphinus capensis) and the short-beaked common dolphin (scientific name: Delphinus delphis). Common dolphins can be found widely distributed in all tropical, sub-tropical and warm-temperate waters. In the Atlantic Ocean, they migrate as far north as Iceland. They are also found in the Mediterranean and Black Seas, the Red Sea, and the Persian Gulf. In the Pacific Ocean, they can be seen as far north as Northern California and Japan, and reach as far south as the southern tip of Africa, South Australia and New Zealand. They also sometimes enter bays and rivers. The long-beaked common dolphin is more often found in coastal waters; whereas, the short-beaked common dolphin is seen more frequently offshore. Both long-beaked and short-beaked dolphins are found in the Southern California bight.

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Physical Appearance

The two common dolphins differ in the length of their beaks or noses. The color patterns on a common dolphin are the most complex of any cetacean. They have 40 - 55 pairs of small pointed teeth on each side of their mouths.

Color: Their back is dark gray to dark black starting from the top of the head continuing down to the tail region. This color pattern dips into a V on the dolphin's sides below the dorsal fin, a distinguishing characteristic of the common dolphin. A tan or yellowish patch is found on both sides of the head along with large dark circles around the eyes. The dolphin's belly is white to creamy-white with a gray colored tail.

Length and Weight: The common dolphin can reach lengths of 8.5 feet (2.6 meters) and weigh up to 300 pounds (135 kg). On average the common dolphin is 5.8 - 8 feet (1.8 - 2.4 m) and weighs 155 - 245 pounds (70 - 100 kg). Males are slightly larger than females.

Fins: The dorsal fin is located near the middle of the back and is triangle-shaped, pointed and curved. It is black to light gray in color with a black border. The dolphin's flippers are long and thin and generally dark in color.

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Like other dolphins, common dolphins hang out in large social groups called pods. Pods of common dolphins range from 1,000 - 100,000 individuals. These dolphins have been known to be friendly and can be seen doing flips and somersaults in the ocean. Dolphins communicate and hunt by means of echolocation.

What is echolocation? Dolphins send out sound waves into the water. When the sound hits an object, it bounces off, and an echo comes back to the dolphin. The dolphin can identify an object by the sound of the echo. The echo's sound tells the dolphin the size, shape and texture of the object the sound wave hits. This is how dolphins find their food and talk with other dolphins.

audioVideo: Common Dolphins Swimming and Leaping

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Breeding and Reproduction

Sexual maturity is reached when the dolphin is 3 - 4 years old, or when they grow to 6 to 7 feet (1.8 to 2.1 meters) in length. Depending on where the dolphins live, they may reach sexual maturity later or earlier in life. The gestation period lasts for 10 - 12 months in the female, with calving peaks in the spring and fall seasons. Calves are 30 - 34 inches (76 - 86 cm) at birth and they nurse for 14 - 19 months.

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The common dolphin, like the bottlenose dolphin, feeds mainly on squid and schooling fish. Octopus, anchovies, herring, cephalopods and pilchards are other marine animals the ommon dolphin can be seen eating. In some parts of the world, the common dolphin can be seen feeding at night. These dolphins like to hang out near local fishing areas, feeding on fish that escape nets or fish discarded by fishermen.

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Fun Facts

  • Like the bottlenose dolphin, the common dolphin loves to ride along side boats and ships.
  • Common dolphins can dive to depths of at least 840 feet (280 meters) for as long as 8 minutes.
  • Common dolphins are fast! It is estimated that they can swim up to 30 miles (48 km) per hour.
  • Common dolphins are the most abundant cetaceans in the Southern California Bight.

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