useless trivia: What Word Means: Censors?

Questions

Common name for any of a group of mainly aquatic arthropod invertebrates, including the crab, lobster, & shrimp?

Common name for any of a large family of luminescent beetles?

Common name for any of a large group of mammals, most of which carry their young in an abdominal pouch after birth?

Common name for any of about 2000 species of two-winged insects (fly)?

Common name for any of about 30 species of long-legged, long-necked wading birds of the same family as the spoonbills?