Nudibranchs (/ˈnjuːdɪbræŋk/) are a group of soft-bodied marine gastropod molluscs, belonging to the order Nudibranchia, that shed their shells after their larval stage.[3] They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to match, such as "clown", "marigold", "splendid", "dancer", "dragon", and[4] "sea rabbit".[5] About 3,000 species of nudibranchs are known.