The molluscs (Haliotis tuberculata, also known as sea ear or green ormer), which grow to around 20 centimetres long, fetch £125 [US$ 196] per kilogram on the Japanese and Californian markets. They are found from the Mediterranean up through the Atlantic coast of France and Portugal, where they are commercially fished. At one stage, the northern limit of their range was the Channel Islands, where they grew so popular as a traditional delicacy that harvesting had to be strictly controlled.