Common starfish

The common starfish is one of the most familiar animals of the seashore. It usually has five arms spreading out from the middle, is often orange or reddish, and has a line of little pale spines down each arm. You can find it in rockpools and out at sea, all around British and Irish coasts.

Even though people call it a starfish, it is not a fish. It belongs to a group called echinoderms, which means “spiny skinned,” together with sea urchins and sea cucumbers. A starfish has no head, no brain, and no blood at all.

Underneath each arm are hundreds of tiny tube feet. The starfish pumps water through them to creep slowly along the seabed and to grip its favourite food — shellfish like mussels and clams. It has a clever, and rather strange, way of eating: it pulls a shell open a crack, pushes its own stomach out through its mouth and into the shell, and turns the meal into soup before slurping it back in.

A starfish has an amazing power. If it loses an arm to a hungry crab or a rough wave, it can slowly grow a new one. Sometimes you will spot a starfish with four big arms and one tiny one that is still growing back.

The common starfish is exactly what its name says — very common along northern Atlantic shores. It has not been checked and listed by the world’s main wildlife watchdog, the IUCN, but experts describe it as widespread and abundant in our seas today.