Mussels © Celia Russell
The secret to this vice-like grip is the numerous fine, sticky threads created in the byssal gland located in the foot. To produce a fibre, a mussel extends part of its foot. It rolls it into a tube then fills it with a concoction of proteins and other substances that subsequently harden into a slender thread.
Byssal threads are strong yet flexible, and help a mussel move around too: it extends and attaches them, then hauls itself forwards. Scientists hope to create new adhesives by studying their amazing ability to stick underwater, on uneven surfaces and in both fresh and salt water.
