Edible sea urchins (Echinus esculentus) in a kelp forest. Sea urchins are echinoderms,relatives of the starfish. Their exoskeleton shell,or test,is covered in numerous spines that protect them from predators. These sea urchins,also known as common sea urchins,are found along the coast of the British Isles,excluding the east coast. They grow to diameters of 16 centimetres and feed on algae,mainly kelp,which they scrape from the surface of rocks. Only the urchins' reproductive organs,roe,are edible. Photographed off the coast of Scotland,UK |