The group includes any type of Crustacean (ISSCAAP division 4). Crustaceans are aquatic animals of various species, wild or cultivated, which have an inedible chitinous outer shell. A small number of species live in fresh water, but most species live in brackish water and/or in the sea. Crustaceans are prepared for wholesale or retail distribution at a "raw" stage, often still live, "raw" and deep-frozen, or cooked directly after catching and deep-frozen. Shrimps or prawns may also be parboiled and thereafter deep-frozen. The part consumed/analysed is by default the whole or a portion of it representing the observed heterogeneity.