The crustaceans (Crustacea) are a large group of arthropods, comprising almost 52,000 described species. They include various familiar animals, such as crabs, lobsters, crayfish, shrimp, krill and barnacles. The majority of them are aquatic, living in either marine or fresh water environments, but a few groups have adapted to life on land, such as terrestrial crabs, terrestrial hermit crabs and woodlice. Crustaceans are among the most successful animals, and are as abundant in the oceans as insects are on land, but even the crustaceans aren’t save from us! The 2008 IUCN Red List of Threatened Species has listed 7 crustaceans as recently extinct.