Ruditapes philippinarum: The $7 billion mollusc

Largely through anthropogenic dispersal, the period since the beginning of the 19th century has seen the global distribution of the Manila or Asari clam expand widely from its indigenous coasts of Japan, Korea, China, and Russia. Today it is found as a naturalised non-indigenous species from the Canadian and US coasts of North America to western Europe from Portugal to Sweden, in the Mediterranean Basin from Tunisia to Turkiye, and in many other places between. In the sedimentary habitats of temperate lagoons, estuaries and intertidal flats, this infaunal bivalve serves as a wild fishery or as cultured stock enhanced by transplanted seed clams from industrial hatcheries. Combining a good range of physiological tolerances with an energetic commitment to reproduction and fast growth, it is now the preeminent cultured mollusc with annual value at first sale of over US$7 billion. This special issue exemplifies the volume and scope of the current international research effort across numerous countries. Many of the contributions originated as presentations at the 5th International Manila Clam (Asari) Symposium held at Kunsan National University in South Korea in June 2024. Subjects range from energetics and reproductive physiology to population dynamics, and from elemental fingerprinting to gene expression. Moreover, the study of R. philippinarum elucidates many current issues and broader research themes in fisheries and aquaculture, non-native arrivals, overfishing, pollution, sustainable development, and climate change. All of which are addressed in this collection.