How do piddocks bore into rock, coral, and concrete?

Piddocks, which are marine bivalve mollusks belonging to the family Pholadidae, are specialized for boring into hard substrates such as rock, coral, concrete, and wood.12

They achieve this by using one end of their two valves, which is equipped with rows of serrated cutting edges. By utilizing these abrasive surfaces, the piddock drills into the material to create a protective burrow. While some species only bore to a depth slightly greater than the length of their shell, others possess extensible siphons that allow them to bore to significantly greater depths. These siphons, which are often protected by tough plates, also enable the animal to feed on minute organisms like phytoplankton while remaining safely embedded within the substrate.1