Living-Earth

Crustaceans (Crustacea) form a very large group of arthropods, some 50,000 described species. Crustaceans have an exoskeleton, which they moult to grow. Most crustaceans are free-living aquatic animals, but some are terrestrial (e.g. woodlice), some are parasitic (e.g. fish lice, tongue worms) and some are sessile (e.g. barnacles). The scientific study of crustaceans is known as carcinology (alternatively, malacostracology, crustaceology or crustalogy). Examples : - Barnacle - Copepod - Crab - Lobster - Krill - Shrimp ...