深海の熱水噴出孔の生物とそこに棲む「生きている化石」蔓脚類

抄録

The most primitive living members of all the suborders in the Cirripedia; Scalpellomorpha, Verrucomorpha, Brachylepadomorpha and Balanomorpha, have been discovered at the deep-sea hydrothermal vents of the Western Pacific. The notable feature here, in contrast to their conservative but distinctly different shell morphologies, is the uniquely convergent adaptation of their setose feeding mechanism to vent-related food sources. Some relatives of them have fossil record in the middle Mesozoic age. It may be puzzling why four such antiquated morphologies have persisted in association with abyssal hydrothermal springs while their antecedents became extinct elsewhere. However, barnacles are noted for their adaptability to a wide range of habitats including rigorous environments such as estuaries and the highest intertidal zone.