Molluscan Immunobiology: Challenges in the Anthropocene Epoch

Abstract

The Mollusca, with a long and rich evolutionary history, is one of the most speciose and distinctive of the animal phyla. Among its members are some of the largest and most long-lived, intelligent, and commercially valuable invertebrate species, contributing massively to the human food supply. Some are valued for their beauty, and others are significant disease vectors. In this chapter, after first providing an overview of the diverse and often distinctive infectious agents with which molluscs must contend, we outline in broad strokes some of the major features of molluscan immune systems. Molluscs continue to enrich our broader understanding of immunology, both from a steady stream of new insights in genomic and postgenomic studies and from novel discoveries such as transmissible neoplasia, which challenge our understanding of cancer and basic processes such as allorecognition. We then discuss how the rapidly changing modern world often exposes molluscs to significant abiotic and biotic challenges—often presented in daunting combinations—that elicit complex responses and reveal the extent to which stress and immune responses are intertwined. We conclude with a discussion of aspects of molluscan immunobiology about which we need to expand our scope of knowledge if molluscs are not to suffer more than they already have in this, the world’s sixth major episode of mass extinction.