Different circumstances such as sampling methodology, sample sorting or taxa distribution among different experts often lead symbiotic associations to remain hidden and the mode of life of the involved partners are either not defined or directly reported as free living. This was apparently the case of
Parahololepidella, a genus proposed by Pettibone (1969) to include
Hololepidella greeffi Augener, 1918, reported as free-living from shallow waters off São Tomé and Cabo Verde Islands (W Africa). In this paper, we report for the first time the symbiotic status of
P. greeffi (Augener, 1918), which lives in association with the antipatharian
Tanacetipathes cf.
spinescens (Gray, 1857), based on new materials collected in São Tomé Island. In addition to the originally described features, the species is characterized by a variable presence of cephalic peaks and by an irregular distribution of elytra from segment 32-33, which may be asymmetrical (within the same individual) and differ between individuals. A list of all known polychaete species associated with antipatharian corals is also provided. We also report new findings of
Gorgoniapolynoe caeciliae (Fauvel, 1913) from deep waters of the Atlantic coasts of the Iberian Peninsula, living in association with the octocorals
Candidella imbricata (Johnson, 1862) (first report for the Spanish waters) and
Corallium niobe Bayer, 1964. The diagnosis of
Gorgoniapolynoe is emended and we suggest that
G. corralophila (Day, 1960) should be referred to a different genus and that
G. pelagica Pettibone, 1991a should be considered as nomen dubium. The Iberian
G. caeciliae fits well with the re-description by Pettibone (1991a), except for the presence of clavate papillae on dorsal cirri, which were neither mentioned nor figured in previous descriptions.
