Form and movement in animals Notes

MOVEMENT IN EARTHWORM

•    An earthworm is an invertebrate.

•    It has a long, tube-like body.

•    It has no bones.

Tube-like body of an earthworm

•    Earthworms live in moist soil which contains organic matter.

•    Earthworms do not have eyes or ears but they have a mouth and are sensitive to heat, light and touch.

•    This adaptation is important for the survival of an earthworm.

MOVEMENT IN SNAIL

•    A snail is a very slow-moving animal.

•    Snails have a shell, inside which they can hide to protect themselves from heat and enemies.

A snail

•    The shell is the outer skeleton, but is not made of bones.

•    They also have a pair of tentacles that bear eyes at the tips.

•    Snails move using a muscular organ called the foot.

MOVEMENT IN FISH

•    Fishes are vertebrates which live in water.

•    All vertebrates have an internal skeleton made up of bones; a tough, elastic substance called cartilage; or both.

•    Most fish have a streamlined shape - the head and the tail is narrow; the middle portion of the body is broader.

•    This kind of shape offers least resistance to the flow of water and makes it easier for them to swim through water.

Fish have streamlined shape