Dolphins have torpedo-shaped bodies. They have a pair of paddle-shaped forelimbs called flippers.
They have no hindlimbs. They have a dorsal fin on their back. They have a powerful tail fins called flukes that propel dolphins through the water.
The dolphins are smooth and rubbery.
Blubber which is a layer of fat that lies beneath their skin and keeps dolphins warm and is a storage place for their food. The blubber helps dolphins stay afloat that is lighter than water.
Dolphins have lungs. Dolphins breathe through a blowhole. The blowhole is a nostril on top of their head.
They seal the blowhole by powerful muscles most of the time while they are underwater.
They have a highly developed sense of hearing. They can hear wide range of low- and high-pitched sounds that includes many that is beyond human hearing.
They have good vision and their body surface has a keen sense of touch. They have no sense of smell and have little sense of taste.
They have a natural sonar system called echolocation. This sonar system helps the dolphins locate underwater objects in their path. They can located the objects by making a series of clicking and whistling sounds. The sounds the dolphin leaves the animals body through the melon.
The melon is an organ of top of their head and consists of a special fatty tissue that directs their sounds foward. Their echoes reflect from an object that is in front of them.
Dolphins may have more than 200 teeth.
The Body of a Common Dolphin includes:
The whale's body features suggest that their body is closely related to hoofed mammals, particulary split-hoofed mammals like cattle and deer. The whales may develop from primitive meat-eating mammals that scientist belived. The oldest fossil of a whale was discovered from about 45 million years ago. About 70 million years ago, whales probably began to develop as most scientists think.
The whale's body features are the same as other mammals. Whales have special cahracteristics that they can live in water. While the whales are living in water, they can grow to size that is enormous. A land mammal can grow so big that their bones and muscles can no longer suppoer thier body weight. The buoyancy(lift) of the water helps support the whale's body and help make it possible for whales to grow more longer than a land animal.
The streamlined shape that enables whales to swim with a minium of resistance shape resembles a fish.
Flukes are whales powerful tail fins that are horizontal instead of vertical like the fish tail fins.
The whales ancestors who lived on land had 4 legs. After the ancestors moved to the sea, their body features changes. The front legs developed into flippers, and the hide legs disappeared over a million years times.
The backbone, ribcage, and shoulder blades of a whale resemble those of other mammals. There are two small bones that are buried in the hip muscles that remain as the whale's hind legs.
The whale's vertebrae are compressed for a short length or joined together into one bone while other mammals have 7 vertebrae. The compressed features keeps the whale's head from moving around when the whale is swimming around. The compressed feature helps the whale's streamlined shape by joining the head directly to the body.
The whale's skin is smooth, rubbery skin that helps the whales swim easily through the water. Whales do not have coat of hair to help them with their insulation like other mammals that have a coat of hair. Whales have a few bristles on their head.
The whales have a layer of skin called blubber underneath their skin. The blubber keeps the whale warm. The blubbler grows up to 6 inces (15 cm) thick. Whales can live off a long period of time on their blubber if food is scarce. The whales have buoyancy with blubber because blubber is lighter than water.
Whales have lungs like other mammals. Whales have to come to the surface regulary to breathe. Baleen Whales breathe every 5-15 minutes but can go up to 40 minutes without breathing. A sperm whale can hold their breath up to 75 minutes.
Whales can go for long periods withouth breathing for certain reasons. Whales' muscles can store more oxygen than other muscles of mammals. Humans can only store 13% of their oxygen supply in the muscles. Whales can only store 41% of their oxygen supply in their muscles. The whale's body reduces the blood flow to the muscles but keeps a normal flow to the heart and brain during a dive which helps save oxygen, the heartbeat is slow. The whale must take several breaths to recharge its tissues with oxygen before diving again after a dive.
The whale rolls forward as it breaks the surface when a whale comes up to breathe. This movement gives whales 2 seconds to blow out and breathe in up to 2,100 quarts (2,000 liters) of air. Blowholes are the whales nostrils which they breathe through and are at top of their head.
The blowhole produces a cloud call blow or spout when a whale exhales. The blow consists of water vapor. Also, it includes mucus and oil droplets. The blow in height is from 6 feet (1.8 meters) in humpback whales to 25 feet (8 meters) in sperm whales. Right whales have a double V-shaped bow. Rorquals have a pear-shaped one. Sperm whales blow forward and to the left.
Whales have no sense of smell. Most species of whales and dolphins have poor eyesight. Toothed whales have limited sense of taste, but most whales can't taste. Whales do have a well-developed senses of touch and hearing. Whales with most of their information about their surroundings. They hear a wide range of sounds. Sounds including low- and high-pitched sounds far beyond the range of human hearing. Whales can tell from what direction a sound coming from underwater unlike people.
Toothed whales produce sounds within the nasal sac system. The nasal sac system are a series of air-filled pouches around the blowhole. The whales can locate underwater objects by listening for the echoes produced when object reflects the sounds. The whales determine the distance to an object and the direction in which it lies from the echoes. This method of navigation the whales are using is called echolocation.
