Barnacle Barnacle A barnacle is a type of arthropod constituting the infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile (nonmotile) suspension feeders, and have two nektonic (active swimming) larval stages. Around 1,220 barnacle species are currently known. The name "Cirripedia" is Latin, meaning "curl-footed". The study of barnacles is called cirripedology. Barnacles are encrusters, attaching themselves permanently to a hard substrate. The most common, "acorn barnacles" (Sessilia), are sessile, growing their shells directly onto the
Barnacle (slang) to a system. The connotation in the software industry is that a software barnacle is code added as an expedient without regard to the original design intent. A software barnacle may also refer to malware or spyware which has been inserted into a computing system illegally. On printed circuit boards, a barnacle may be as simple as cutting a trace, soldering a wire in order to connect two points on the circuit board, or adding a component such as a resistor or capacitor. A barnacle may also be a complex subassembly or daughterboard. Barnacles in hardware assemblies allow an engineer