Movement In Earthworm
An earthworm is an invertebrate. It has a long, tube-like body. It has no bones. Its body shape is maintained by the fluid present inside its body. This kind of skeleton is called a liquid skeleton.
An earthworm’s body is made up of several parts called segments.
It moves by lengthening and shortening these segments. It extends the front part of the body, keeping the rear end fixed to the ground. Then it fixes the front part and pulls the rear end. Its movement can be compared with that of a spring. Its body secretes a slimy substance to help in the movement. The segments also have tiny, hair-like bristles, which help the earthworm to grip the surface and pull its body forward.