by Claudine RENAUD Agence France-Presse Villefranche-sur-Mer, France (AFP) — With wing-shaped shells lined with iridescent mother-of-pearl and producing the fibers of rare and delicate sea silk, the noble pen shell clam is one of the most emblematic species in the Mediterranean and a bellwether for marine environmental health. But the giant mollusk, the world’s second biggest, is under mortal threat from a parasite that has ravaged populations since it was identified along Spanish coasts in 2016. Scientists […]