Megabalanus stultus
Megabalanus stultus is a species of barnacle first described by Charles Darwin in 1854. It lives on fire corals of the genus Millepora in the Atlantic Ocean from Florida to southern Brazil.
Ecology
Megabalanus stultus is one of three species of barnacle that live on fire corals. Savignium milleporae lives in the Indo-Pacific and lives on 9 species of Millepora; Megabalanus ajax lives in the western Pacific and lives on Millepora platyphylla; Me. stultus lives in the western Atlantic, and lives on Mi. alcicornis and Mi. complanata. The nature of the relationship between M. stultus and the coral is unclear. At low densities, the barnacle has no discernible effect on the coral, but high-densities of coral-inhabiting barnacles can disrupt the growth of the colony.Distribution
In his original description of the species, Darwin reported that M. stultus occurred in Singapore and the West Indies. In 1968, Arnold Ross considered the reports of M stultus from the Pacific Ocean to be erroneous, limiting the type locality to the West Indies. M. stultus has subsequently been reported from Taiwan in the western Pacific, and those records have been reassessed as referring to the related species Megabalanus ajax.M. stultus is now thought to occur exclusively in the western Atlantic, including the Caribbean Sea, from Florida to Rio de Janeiro, Brazil.