Barnacle is a type of aquatic organism that belongs to the CRUSTACEAN family. It is a sessile organism, meaning it does not move from its place of attachment. It has a hard outer shell and uses CIRRI, which are feathery appendages, to filter food from the water. Barnacles are often found attached to rocks, hulls of ships, and other surfaces in the ocean. They are also known to be parasites, leeches, and even predators of other organisms. They have a sticky substance called TAR that helps them attach to surfaces. Barnacles can also be found in the AFT of ships, where they are known as 'GOOSE barnacles'.