 Some species of marine mussel, including the Blue mussel ("Mytilus edulis") and the New Zealand green-lipped mussel ("Perna canaliculus"), are also cultivated as a source of food.In some areas of the world, mussel farmers collect naturally occurring marine mussel seed for transfer to more appropriate growing areas, however, most North American mussel farmers rely on hatchery-produced seed.Growers typically purchase seed after it has set (about 1mm in size) or after it has been nursed in upwellers for 3-6 additional weeks and is 2-3mm.