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 repair design errors, experiment with design changes or enhancements, or otherwise alter circuit behaviour. Although usually a barnacle-implemented change is incorporated into a new fabrication cycle circuit before production, occasionally there are final-assembly barnacles. In such cases it is determined to be less expensive to add a barnacle to a final, shipping product rather than re-spin the circuit to ship without these interventions left in place. The normal development cycle for electronic hardware contains two main phases. The first phase is the development and prototype phase in which the hardware is first designed (and often simulated using a computer