The male releases millions of sperm which
fertilises the eggs.
Starfish move by using a water pumping
system. This is connected to their feet.
They draw water in and pump it out to
lengthen or shorten their feet. This enables them to climb and cling
to rocks.
Most starfish are predators.
Sea stars, sea urchins and sand
dollars all belong to the same group called echinoderms.
Cushion Star
The most common starfish are cushion
stars. You will find them in rock pools. They cling tightly to rocks
or under stones.
They have five arms.
Their colours range from yellow to purple.
Greyish green is the most usual colour.
They have tube feet tipped with suckers.
These are on the underside of their arms.
They browse on filmy green seaweeds and
digest them by extruding their stomach over them. They also feed on
matter found on the bottom of the sandy pools.
Sun Stars
Sun stars love to eat mussel.
They hold the mussel in their arms and
pull it apart with hundreds of their feet working in relays.
At the same time the starfishes stomach
also secrets an acid fluid which puts the mussel to sleep.
When the mussel is pulled apart the
starfish extrudes its stomach through its mouth and digests the
mussel.
Starfish topic words.