European Edible Sea Urchin

E. esculentus is approximately spherical but slightly flattened at both poles. It is reddish or purplish with white tubercles and grows to about ten centimetres in diameter. The brittle, limy test is rigid and divided into five ambulacral areas separated by five inter-ambulacral areas. There are two rows of plates in each of these areas, making twenty rows of plates in total. The test is covered in spines each articulating with a tubercle. There is a dense covering of secondary spines and a smaller number of longer, primary spines, carried on each second or third ambulacral plate. The spines are blunt ended and usually white with purplish tips. There is a radially symmetrical pattern of holes in the ambulacral areas through which the tube feet emerge.

In the North Sea, the species is common in all areas with hard substrates. It is found off the coasts of Portugal, Spain, France, Belgium, the Netherlands, Denmark, Norway, Iceland, Sweden, the United Kingdom and Ireland.

The species name esculentus means "edible". Sea urchin roe is used as food around the world, but esculentus is not among the preferred sea urchin species, due to its white gonads. Sea urchin species with orange gonads are preferred. It is not actually the eggs that are eaten but the gonads, both male and female. Fishing for urchins is undertaken off European coasts and the possibility of aquaculture is being investigated. In a study off the west coast of Scotland it was found that feeding a commercially available salmon feed promoted gonadal growth in the urchins and the practicalities of a fully farmed approach were being assessed.