Starfish

Common starfish
Taken by Kieran Boyce, Dublin University Sub-Aqua Club

A starfish is one of the most interesting looking animals along the sea-shore. Starfish can also be found living in coral reefs. It is shaped just like a star and doesn’t look at all like an animal! It usually has five arms, but some starfish have more.

Did you know that if a star fish loses one of its arms, it can grow it back again?!

A starfish doesn’t have a skeleton of bones to give it shape and help it to move. Instead, it has lots of tiny canals inside its body that are filled with water.

These canals are joined to tiny little ‘tube feet’ on its skin. When the starfish wants to move along the shore, some of these ‘tube feet’ are filled with water to help it crawl along. As you could guess, it takes a long time for a star fish to move from place to place!

Cartoon Mussels
Courtesy of Loren Collits

Some of the starfish’s favourite meals are mussels, oysters and clams. To open their shells, starfish simply cling on tight with their tube feet and pull . . . and pull . . . and pull until the poor shellfish gets tired and opens its shell. Then the starfish turns one of its two stomachs inside out, squeezes it though the gap in the shell and dissolves to poor shellfish inside.