The 10- to 20-centimeter-long lugworms breathe through gills, like fish, but they spend half their lives out of water.

Why do Lugworms have external gills?

Lugworms also have hairs on the outside of their bodies that act as external gills. These can rapidly increase its uptake of oxygen. Lugworm blood has a large oxygen carrying capacity which may have medical applications.

Can humans eat Lugworms?

Scientists are excited by the potential of lugworm hemoglobin — although they also point to a rigorous testing procedure before the molecule can be certified as safe and effective for humans.