Physical Description • Starfish are hard-skinned animals which have spines that help to protect them. • They dont have bones and they are NOT fish, they are Echinoderms: spiny-skinned invertebrates that live on the ocean floor. • Other echinoderms are the sea cucumbers and the sea urchin.
Feeding • Starfish are carnivores, they eat clams, oysters, coral and mussels. • It grasps the tightly closed shell of the oyster with the tube-feet on its arms and tugs and pulls until it has opened a small crack in the shell. Then it sticks its stomach out through its mouth and gets it into its prey’s shell. The soft body of the mollusc is digested and the starfish then pulls its stomach back to its body. • While it is eating it often gives off a special poison that drives away the other starfish so that they don’t take its food
Locomotion and Interesting Facts • Starfish move very slowly along the sea floor using hundreds of tiny tube-feet, that are like little tubes with a circle at the end, that help it to walk and climb; if a wave moves the starfish it will hold onto a rock with its tube feet. • If a starfish loses one arm it will grow again easily.
Starfish’s Brain • Starfish do not have true brains. They have a cluster of nerves called ganglia that form a ring in the centre of the starfish. • With the exception of eye spots in the tip of each arm there are no specialised sense organs (such as eyes or ears). These eyespots sense light and smell.