Dolphins Outline v Dolphins Definitions v Dolphins Physical

Dolphins

Outline v. Dolphins Definitions. v. Dolphins Physical Characteristics. v. Dolphins Behavior v. Dolphins Respiration. v. References.

Outline v. Dolphins Definitions. Dolphins Physical Characteristics. Dolphins Behavior Dolphins Respiration. References.

Dolphins Definitions Dolphins are a widely distributed and diverse group of aquatic mammals. They are an informal grouping within the order Cetacea, excluding whales and porpoises, so to zoologists the grouping is paraphyletic.

Outline Dolphins Definitions. v. Dolphins Physical Characteristics. Dolphins Behavior Dolphins Respiration. References.

Dolphins Physical Characteristics There are many characteristics that characterize dolphins, these include : 1. 3. 5. 7. 9. Size Skin Flukes Head Eye Glands 2. Body Shape 4. Pectoral Flippers 6. Dorsal Fin 8. Teeth 10. Ears

1. Size In general, bottlenose dolphins are 2 to 3. 9 m. Their average weight is 150 to 200 kg. Differences in size may be related to coastal and offshore ecotype variances, and geographical locations. Offshore ecotypes, adapted for cooler waters, tend to be larger than inshore ecotypes.

2. Body Shape A bottlenose dolphin has a sleek, streamlined, fusiform body.

3. Skin A dolphin’s skin is smooth and feels rubbery. The skin has no hair or sweat glands. The outer skin layer (epidermis) is about 10 to 20 times thicker than the epidermis of terrestrial mammals.

4. Pectoral Flippers A dolphin's forelimbs are pectoral flippers. Pectoral flippers have the major skeletal elements of land mammal forelimbs, but they are foreshortened and modified. The skeletal elements are rigidly supported by connective tissue. Pectoral flippers are curved back slightly and pointed at the tips. Pectoral flipper length averages 30 to 50 cm (11. 7 -19. 5 in. ).

5. Flukes Dolphins use their pectoral flippers mainly to steer and, with the help of the flukes, to stop. A dolphin's pectoral flipper contains five digits similar to that of a human hand.

5. Flukes … Each lobe of a dolphin's tail is called a fluke. Flukes are flattened pads of tough, dense, fibrous connective tissue, completely without bone, cartilage, or muscle. Longitudinal muscles of the back and peduncle (tail stock) move the flukes up and down to propel a dolphin through water.

6. Dorsal Fin A bottlenose dolphin's dorsal fin is often falcate (curved back), although the shape is quite variable. It is located at the center of the back. Like the flukes, the dorsal fin is made of dense, fibrous connective tissue, with no bone, cartilage, or muscle. As in the flukes and the flippers, arteries in the dorsal fin are surrounded by veins to help conserve or dissipate body heat.

7. Head The rounded region of a dolphin's forehead is called the melon. The melon contains fat and plays an important role in dolphin echolocation.

8. Teeth are conical and interlocking. Teeth are designed for grasping (not chewing) food. Bottlenose dolphins have 18 to 26 teeth on each side of the upper and lower jaws, a total of 72 to 104 teeth. A tooth's diameter measures about 1 cm (0. 4 in. ). Dolphin teeth are not replaced.

9. Eye Glands at the inner corners of the eye sockets secrete an oily, jelly-like mucus that lubricates the eyes, washes away debris, and probably helps streamline a dolphin's eye as it swims. This tear-like film may also protect the eyes from infective organisms.

10. Ears, located just behind the eyes, are small inconspicuous openings, with no external pinnae (flaps).

Outline Dolphins Definitions. Dolphins Physical Characteristics. v. Dolphins Behavior Dolphins Respiration. References.

Dolphins Behavior Dolphins are well known for their agility and playful behavior, making them a favorite of wildlife watchers. Many species will leap out of the water, spy-hop (rise vertically out of the water to view their surroundings) and follow ships, often synchronizing their movements with one another. Scientists believe that dolphins conserve energy by swimming alongside ships, a practice known as bow-riding.

Dolphins Behavior Dolphins live in social groups of five to several hundred. They use echolocation to find prey and often hunt together by surrounding a school of fish, trapping them and taking turns swimming through the school and catching fish. Dolphins will also follow seabirds, other whales and fishing boats to feed opportunistically on the fish they scare up or discard.

Outline Dolphins Definitions. Dolphins Physical Characteristics. Dolphins Behavior v. Dolphins Respiration. References.

Dolphins Respiration Dolphins breathe in air through their blowhole. The blowhole is covered by a muscular flap which provides a watertight seal. The flap opens during contraction and closes during muscle relaxation.

Dolphins Respiration For them to be able to breathe, they have to rise to the surface and breathe in the oxygen. When a dolphin breaths in air it goes directly into their lungs, exhaling and inhaling rarely takes more than 0. 3 seconds and they take about 2 -3 breathes per minute on average. During each respiration a dolphin exchanges 80% or more of its lung air.

Dolphins Respiration When diving, the dolphin reduces its request for oxygen. Their heart beats slower and the amount of blood pumped around the body decreases. During a deep dive only important organs such as the heart and brain get oxygen rich blood flowing through them.

Outline Dolphins Definitions. Dolphins Physical Characteristics. Dolphins Behavior Dolphins Respiration. v. References.

References www. presentationszone. com www. wikipedia. org www. seaworld. org www. defenders. org www. dolphin 4 life. weebly. com