Knights of the Shining Piddock

The Pholas dactylus, or common piddock, is a shellfish with a simple lifestyle - it glows in the dark, breeds and dies. Its enemies are pollution and the Mediterranean gourmets who eat it as an hors d'oeuvre. Although on the verge of extinction, it also looks set to revolutionise the treatment of diabetes, arthritis and heart disease and make a fortune for two scientists. Fifteen years ago Jan and Robert Knight discovered a mutual enthusiasm for the marine mollusc. Working from their dining room, they extracted its luminescent juice and discovered that it has a wide range of applications in medical diagnosis. Now the chemical they called Pholasin has aroused enormous interest among research organisations as well as a Kent oyster farmer who has started a piddock farm for them. Griff Rhys Jones narrates the remarkable story of the piddock, the couple who have devoted their lives to it, and the prototype of the medical kit that could make them millionaires.