Until recently you could still argue about exactly how many arms a starfish has. Two, or five? Research from the universities of Southampton and Stanford puts an end to that debate. The body regions of the sea animals were mapped using advanced genetic techniques.
What seems? A starfish has no arms. No body either. It only has ‘bulges’ on the head. “The head is everywhere. The starfish is basically a crawling head,” says biologist Dirk Draulans in ‘New Facts’.
Age-old mystery unraveled
Why the starfish has its typical shape is a question that has puzzled scientists for centuries. “Most animals we know are doubly symmetrical, just like us. They are a mirror image of themselves: the left and right halves are virtually the same.” Starfish are a notable exception to this.
Although they do comply with that rule at an early stage. “As an embryo and larva, starfish also have that double symmetry, with a head, torso and tail.” During the course of development, a metamorphosis takes place.