whale
Whales/Cetaceans
Cetaceans are a group of mammals characterized by spending their whole lives totally in water. The word cetacean is derived from both greek and latin words meaning whale. However, not only are whales part of the cetaceans but dolphins and porpoises as well. This can be confusing when all cetaceans are referred to as whales. They are warm blooded, give birth to live young, and nurse with mammary glands. They also breathe air with lungs unlike the fish that remove oxygen from the water. Whales have a streamlined shape to glide through the water with ease. Where is the hair characteristic of mammals? Well, they are nearly hairless because of drag issues but there are some bristles usually found on the head. They have elastic skin and a thick layer of fatty blubber. Their nostrils are on top of their head to facilitate breathing without having to lift their whole head out of the water. Their tail flukes act as giant paddles that power them through the water by undulating up and down. The forelimbs are the flippers and the hind limbs are absent or not usable. Whales are further divided into two physically different groups. The toothed whales (odonotcetes) include those such as the orcas, sperm whales, pilot whales, beaked whales, narwhals, belugas, dolphins, and porpoises. The baleen whales (mystocetes) include those such as the gray whales, blue whales, minke whales, humpback whales, and right whales.
Acrobatics
Cetaceans perform different kinds of acrobatics in the water including breaching, spyhopping, lobtailing, and logging. Breaching is an activity involving jumping high out of the water and then slapping the water as they come back down. They may even twirl around while breaching. Sometimes a whale will poke its head out of the water and turn around and is called spyhopping. Lobtailing involves sticking their tail out of the water, swinging it around, and then slapping it on the water's surface. This will make a very loud sound. Finally, logging occurs when the whale lies still at the surface of the water probably resting and parts of the back and dorsal fin are exposed at the surface.
Behavior
Cetaceans are said to have strong social ties and are strongest between mother and calf. Social groups of whales are called pods. Whales use sonar and may be heard for miles under the water. These are often called whale songs. It is used in attracting mates, to keep track of offspring, and for the toothed whale, to catch prey.
The general term "whale" refers to the 'great whales' which includes the largest of all the toothed whales, the sperm whale, and all of the large baleen whales.
Work Cited
Osborne, R., Calambokidis, J., and Dorsey, E.M. A Guide to Marine Mammals of Greater Puget Sound. Island Publishers, 1988.
