Blue Mussel - Mytilus edulis

On the left in this photo is a small mussel. It has attached itself to a snail with structures called byssal threads. The byssal threads are secreted as a liquid by a gland near the mussel's foot, and then the threads harden upon contact with water. They are pretty strong, but can be ripped if you pull hard enough. They allow the mussel to anchor itself to nearly any surface. The tiny hairs on the mussels shell are probably for tactile perception and/or a defense against predators.

Habitat: Found in a tidal pool during low tide