Mussel beards or Byssus are natural fibres created by bivalve mollusks, useD to anchor themselves to rocks, substrates, or each other.
In edible mussels, the byssus, often referred to as the "beard," is an inedible part that is usually removed during the current industrial mussel cleaning process. A machine cuts off all the mussel fibres, which are then gathered in containers and commonly disposed of in landfills or used as biomass.