The sea urchin is a mollusc that lives on the rocky ocean floor, and is known for its unique taste and texture. It has a round, spiny shape, with a hard shell protecting its soft body. It is characterised by its spherical carapace, formed by calcareous plates joined together, covered with rigid, sharp spines that serve as a defence against predators.
There are many different species of sea urchins around the world, but the most commonly used in gastronomy are those of the family Echinoidea. It is a highly valued ingredient in the cuisine of many coastal regions.