The cetacea order consists of whales dolphins and their relatives. Common attributes shared by these animals. Insight into eating habits and habitats.
The Cetacea are an order of water mammal which includes whales, dolphins and their relatives. This order consists of 38 genera and 90 species of animals. Despite the fact that they are mammals and breathe air, they spend their entire lives in the water, their bodies adapting and evolving many structural modifications that help them live an aquatic life.
With bodies shaped like torpedoes, their front limbs are modified into flippers. They don't have any hind limbs, instead using their powerful tails to propel them through the water. The tails of cetacea are a horizontal fluke instead of a vertical tail like fish. As a general rule, their bodies are hairless, aiding them in aerodynamically cutting through the water. Under their skin, the cetacea have a layer of oily fat. This layer insulates them in cold water and helps them to float. They have no external ears and their nostrils are set at the top of their heads in the form of a blowhole. The position of the blowhole better allows the animals to breathe air without choking on water. The bones of a cetacea are spongy and filled with oil, also helping them to float. Their eyes are protected by a greasy secretion.
Similar to other mammals, cetacea nurse their young. However, their calves do not suck milk. If they attempted this, they would probably get a mouthful of water mixed in with their milk. Instead a mother cetacea uses a ring of muscles located around the mammary glands to squirt their milk right into the mouths of their young. Unlike humans though, the mouth of a cetacea is not connected to its lungs, thereby eliminating the possibility of water entering by accident.
Cetaceans are great divers. Their bodies are modified to allow them to withstand great pressures far beneath the surface. Oxygen and the chemicals in the blood combine, and are released by the muscles the supply them with oxygen while they are underwater and cannot surface for air. The circulatory system pulls blood towards the brain, which redirects the oxygen to the area that needs it most, until they come up for air. Unlike humans, a quick ascent to the surface does not create dangerous gaseous bubbles, thus eliminating the danger of the bends.
Cetaceans do not have a sense of smell. Their hearing and touch are the most acute senses, even bypassing vision as the primary sense. Certain cetaceans make a variety of sound underwater. These sounds are used to orient themselves. By listening for the echoes of these sounds, some cetacea can determine where they are in relation to other objects in the water. This process, which is similar to a sonar is called echo location. It is also believed that these sounds are a complex form of language. This language, combines with their great brain size has led researchers to believe that cetacea are highly intelligent. Researchers now believe that some whales may be as intelligent or more intelligent than humans. In the early 70s, the whaling industry was rapidly exterminating one species of whale after another, however, efforts by many agencies have slowed this process and protected our cetacea friends.
