Mytilus galloprovincialis, Perna perna and Semimytilus algosus
Mussels are fast becoming South Africa’s biggest source of income from marine products and the industry is gaining a considerable export market. Mussels are marine molluscs of the class Pelecypoda, which means hatchet-foot. They are bivalves, having a shell consisting of two valves, or movable pieces, hinged by an elastic ligament.
Within the shell there is a fleshy layer of tissue called the mantle with a cavity (the mantle cavity) between the mantle and the body wall proper. The mantle secretes the layers of the shell, including the inner nacreous, or pearly, layer. Nacreous layers can also be formed around a foreign body in reaction to irritation...Read More