Locomotion in Animals
Locomotion in animals
Animals have different ways of movement or locomotion depending upon their habitat and body structure.
Movement in animals is essential for their survival.
Depending upon their environment, the animals run, hop fly or swim.
Muscles and bones help in the movement of animals. But there are animals who do not have bones, but still they have their own means to move from one location to another.
We will learn about various means of locomotion in animals.
Earthworm is a small worm which mostly lives in the soil.
•Earthworms can move easily on hard surfaces.
•Earthworms move with help of tiny, bristle like projections called setae.
•The body segment of the earthworm possesses setae which help in their movement. Setae help the earthworm in getting firm hold on the ground.
•Earthworms move forward by repeated contractions and relaxations of their muscles in the skin.
•A slimy substance secreted by the earthworm helps in its movement.
Locomotion in cockroaches
•Six legs of the cockroach help it to walk, and two pairs of wings help it to fly.
•Cockroach does not possess any bones.
Locomotion in earthworms
•The body is covered with hard made up of chitin.
•Exoskeleton is a jointed structure which helps in the movement of the body.
•A cockroach moves its legs with the help of muscles near the limbs.
•It uses its breast muscles to move its wings and fly.
•A cockroach can walk, fly and even climb.
Locomotion in snails
•Snail is protected by its hard external skeleton called as shell.
•Snails are found in wet places.
•Entire body except the foot lies inside the shell. When disturbed, snail even retracts the foot in to the shell. Snail moves with the help of single muscular foot.
•The under surface of the muscular foot is lubricated with mucus. The muscular foot glides over the surface. The rhythmic contractions and relaxations of this muscular foot brings about pulling action in the body.
•The secreted mucus also reduces the risk of injury from sharp objects.
Gait of fish
Fish is a vertebrate with vertebral column in its body.
•The body of the fish is supported by endoskeleton made up of bones.
•Fish possess a streamlined body which helps them to swim in water. Fish swim with the help of their fins. The tail flaps from side to side to make them swim in the right direction.
•Some fish, however, move by bending their bodies from one side to another in quick succession. This produces a thrust that helps it move forward.
•Movement of fish in water is also supported by air bladder filled with air. It helps the fish to rise or dive deep into water.
Gait of snakes
Snakes are vertebrates with vertebral column.
•Body is supported by a skeleton made up of vertebrae which run continuously from head to tail.
•As they do not have any limbs, snakes do not have appendicular skeleton.
•Snakes move in a loop-like, zig-zag manner. They cannot move in a straight line.
•They have difficulty in moving on very smooth surfaces.
•Snakes have a long back bone and many interconnected muscles that help them to slither.
•They have muscles connecting the backbone, ribs and skin.
•Snakes move in grass, sand and water. Though the snakes do not have arms or legs, they can climb trees.
Gait of birds
Birds are arboreal in habit. Birds exhibit two types of locomotion.
•They fly in the air. They can also walk.
•A bird has a body best suited for flight.
•Forelimbs are modified into its wings.
•Birds have light and hollow bones.
•The breast bones are connected to strong muscles which help them to flap their wings during flight.
•The tail controls the direction of flight. Birds have very strong shoulder bones.
•Birds can walk and perch on trees with the help of their hind limbs.
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