A new species of Pycnogonida, Anoplodactylus ophiurophilus, is described. It is associated with three species of the genus Ophiocoma in the Seychelles (Indian Ocean) and constitutes the first recorded case of a sea spider found on Ophiuroidea. In comparison with the 83 species actually recognized in Anoplodactylus, the new species shows hardly any morphological adaptations due to this remarkable association.