Crustaceans are among the most commonly consumed seafoods. Crustaceans belong to the Arthropod family. Crustaceans are divided into six major subgroups that include 44,000 species. Amongst these is a variety of commonly and less commonly eaten sea foods like langoustine, lobster, crayfish, and crab. Other sea foods like clams, mussels, oysters, scallops, abalone and squid are no crustaceans but molluscs. Crustacean allergy is a so-called IgE-mediated food allergy. IgE (Immunoglobulin E) is the allergy antibody.