Cladosiphon okamuranus

Cladosiphon okamuranus (モズク; 水雲; 藻付; 海蘊; 海雲, mozuku) is a type of edible seaweed in the genus Cladosiphon, naturally found in Okinawa, Japan. Most mozuku is now farmed by locals, and sold to processing factories. The main use of mozuku is as food, and as a source of one type of sulfated polysaccharide called Fucoidan, which is used as a cancer treatment aid and health supplement.