The fundamental role of the cyprid larvae is to select an appropriate host species, locate a suitable site on the host, then settle and metamorphose. The juvenile and adult barnacle will permanently occupy the location that the cyprid has selected.
Several authors have studied in detail the distribution of cyprid larvae and metamorphosed Octolasmis on the anatomy of their hosts. For example, on an individual crustacean host there may be three or four species of Octolasmis occupying positions on both the exposed outer surfaces of the body as well as locations within the host’s gill chamber. Detailed studies (e.g., see references below) have begun to document instances both of overlapping and non-overlapping species distributions on hosts.