They can be very dangerous animals.
They have many small feet that they use to move along the bottom of the ocean.
Their body is full of holes, known as pores.
They are fixed to the ground so they cannot move around.
Some of them are aquatic and live in water.
Some of them live in water.
They have a long soft segmented body that is made up of rings.
This earthworm inside moist soil.
Food and water enter their body through these pores.
They have poisonous tentacles that they use to defend themselves.
They live at the bottom of the sea.
Nearly all of them have a shell.
Starfish and sea urchins belong to this group of invertebrates.
Some of them are terrestrial and live on land.
All of them have soft muscular bodies that they use to move along the ground or through the water.
