Dolphin: These creatures jumping the waves
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- How often have you walked along the sea shore looking into the waves for a sight of these creatures, who love jumping the waves, or watched them perform in an aquatic park and wanted to find out more?
- Over thDolphins have smooth, rubbery skin. The color is usually a mixture of black, white, and gray. Dolphins have two flippers, or fins, on their sides as well as a triangular dorsal fin, which is a fin on their back. Like other whales, they have an insulating layer of blubber (fat) beneath the skin. Although they are similar in appearance to porpoises, dolphins have a beaklike snout. Porpoises have short, blunt snouts. In addition, the teeth of dolphins are cone-shaped, while those of porpoises are flatter.ins and porpoises. There are numerous stories about people who have been rescued by dolphins and it has helped create a love for and folklore about these magnificent creatures.
- The dolphin's tail, which propels the animal in its lunges and dives, is horizontal rather than vertical like the tails of fishes. Dolphins are noted for being graceful swimmers. They move in long, slow curves that bring the head to the surface of the water and then expose the back fin as the animal dips downward. At first glance, the high dorsal fin somewhat resembles that of a shark. Dolphins are also swift swimmers. The bottlenose dolphin can attain speeds of nearly 18 miles (30 kilometers) per hour in short bursts, and common dolphins can swim even faster.
Dolphins use their teeth to seize their food. They typically eat marine fish and larger invertebrates (animals without backbones), such as squid. River dolphins spend much of their time at river bottoms, using their snout to find fish and crustaceans (hard-bodied invertebrate animals, such as crabs) in the mud.The social behavior and organization of dolphins are among the most complex and advanced among all animals. Dolphins use a communication and detection system in the form of underwater sonar that consists of high-pitched whistles and squeaks. Some of these sounds may be of ultrasonic frequency-that is, above the range of human hearing.
Dolphins are able to detect objects underwater by using echolocation, where t
he sounds they make are reflected off solid surfaces back to their sensitive ears. The time it takes for a reflected sound to return indicates how far away an object is from the dolphin.
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