Information about sea urchins.

Hedgehogs belong to a large group of animals called "echinoderms" meaning the Greek, spine and skin.

Other strange animals are also part of this group such as starfish, but only sea urchins and sea biscuits have shells.

There are about 800 varieties of hedgehogs in the seas of the world, discovered by now.

Although ancient animals have adapted to all kinds of marine environment from polar to tropical areas.

Hedgehogs like photo, cidaris, are covered with thin spikes, living in waters of the Mediterranean and the Atlantic.

Pea urchins, are the smallest of the seas of Europe and are at the edges of the beaches.

The carapace of sea urchins is made up of a series of plates that protects the soft parts.

The sea urchin spikes serve to protect and move, as well as hidden or buried.

The urchins are fed by a mandibular device, similar to a peak consisted of 5 teeth, this part always points to the seabed.

Reproduction of sea urchins is somewhat complicated, there are hedgehogs and hedgehogs sexually reproducing asexually reproducing.