Common Piddock

• It gives off a blue-green light from several parts of its body; Pliny the Elder already described how it glowed in the mouth of anyone who ate it.
• The physiologist Raphaël Dubois coined the terms luciferin and luciferase in 1887 while studying the bioluminescence of this very species.
• It bores into rock by mechanical abrasion, turning its shell, not with acid.
• It is bioluminescent: when disturbed it shoots a glowing blue secretion out of its siphon.
• Its light has a historic place in science. Pliny the Elder described it in the first century, and in the late nineteenth century the French pharmacist Raphaël Dubois used it to describe for the first time the oxygen-dependent luciferin-luciferase reaction, which turned out to be universal in bioluminescence.
• The protein responsible is called pholasin, and today it is produced recombinantly and used in the laboratory as a sensitive indicator of reactive oxygen species.
• It bores into rock mechanically, rasping with the teeth on the front of its shell while rotating on its own axis.
• It was a highly prized delicacy in Europe, as it already had been in imperial Rome.

Skeleton type

Invertebrate - external calcareous bivalve shell (mollusc)

Habitat and environment

Soft rock, clay and peat in the intertidal of the Mediterranean and the Atlantic

Sources consulted: Wikipedia (es): Pholas dactylus