Fig. 7
From: Surface Sensing and Settlement Strategies of Marine Biofouling Organisms
A simplified life cycle for a generalized thoracican barnacle, illustrating site selection and settlement by a cyprid followed by metamorphosis. Letters (A–E) indicate stages in the development of a barnacle and numerals (i–vi) indicate behaviors. A is a juvenile barnacle. Within a few months this barnacle will be sexually mature and able to release nauplii, (B) into the water column from eggs brooded within the mantle cavity. After feeding in the water column for days to weeks (i–ii) the nauplii metamorphose into cyprids (C). When competent, the cyprids migrate to the benthos (iii) and explore surfaces, depositing footprints as they explore (D). Cyprids may re-enter the water column if the surface is not satisfactory, thus delaying settlement (iv), or settle immediately (v) if stimulated to do so. (E) A permanently attached (settled) cyprid. Within 12 h of permanent attachment, a cyprid will complete metamorphosis (vi) into a juvenile barnacle (A) (reproduced from [91], reprinted by permission of Taylor and Francis Group Ltd, http://www.informaworld.com)