Mozuku is a term for the brown seaweed that is harvested in the Japanese waters, but predominatly around Okinawa. Most popular type is Okinawa mozuku (lat. Cladosiphon okamuranus), but there are also ito mozuku (lat. Nemacystus decipiens), ishi mozuku (lat. Sphaerotrichia divaricata) and futo mozuku (lat. Tinocladia crassa).
This seaweed is characterized by its slimy texture and stringy appearance, making it quite distinct from other types of edible seaweed like nori or wakame. Mozuku is highly prized for its nutritional benefits, including a high content of fucoidan, a type of sulfated polysaccharide known for its potential health benefits such as anti-inflammatory properties, immune system support, and possibly anticancer activities.