Sabelliphilidae (Copepoda: Cyclopoida) associated with the tube anemone Pachycerianthus maua (Carlgren) and the horseshoe worm Phoronis australis Haswell off New Caledonia.

Examination of washings of the ceriantharian Pachycerianthus maua (Carlgren) and its phoronid symbiont Phoronis australis Haswell in New Caledonian waters revealed two species of symbiotic copepods belonging to the family Sabelliphilidae (Cyclopoida). Phoronicola spinulatus Boxshall & Humes, 1988, the only other copepod known to be associated with a phoronid and originally described from Hong Kong, was found on both the lophophore of Phoronis australis and the tentacular crown of Pachycerianthus maua. Both sexes of Phoronicola spinulatus are redescribed based on the New Caledonian material and re-examination of the type-material revealed some observational errors in the original description. Myxomolgus hoi n. sp. was exclusively found on the ceriantharian host and appears most closely related to its only known Pacific congener, M. invulgus Kim, 2001, in lacking the strong spines on antennulary segments 1-2, the presence of closely set, fine teeth along the convex margin of the mandibular blade, and the absence of a proximal bulbous protrusion along the inner margin of leg 5 exopod. Differences between both species are found in the rostrum, antennule, antenna, maxillule, leg 4, caudal rami and body size. The relatively low number of specimens of P. spinulatus recovered from washings of the lophophores (and its presence on Pachycerianthus maua) suggests that its real host is a ceriantharian rather than a phoronid. It is conceivable that both Phoronicola spinulatus and M. hoi n. sp. live and feed on/inside the mucilaginous ceriantharian tube rather than on the lophophore or tentacular crown of their respective hosts.