Buhl-Mortensen and Mortensen (2004) surveyed the crustacean fauna associated with P. resedaeformis from samples taken in the Northeast Channel off Nova Scotia. They recorded seven apparently coral-associated species: Enalcyonium cf. olssoni (Copepoda); Ornatoscalpellum stroemii (Cirripedia); Munna boecki (Isopoda); Metopa bruzelii, Proboloides calcarata, and Stenopleustes malmgreni (Amphipoda); and Pandalus propinquus (Decapoda). In addition, they recorded an unidentified cypris larva (Cirripedia) and two species known to be pelagic and not regarded as coral-associated fauna, Sergestes arcticus (Decapoda) and Themisto compressa (Amphipoda).

Krieger and Wing (2002) note that few in situ observations have been made of deepwater corals and, as a consequence, little is known of their ecology. They observed Primnoa from a manned submersible at 11 sites in the Gulf of Alaska from 1989 to 1997 at depths of 161 to 365 meters. They identified 10 megafaunal groups that associate with Primnoa to feed on the coral, use the coral branches for suspension feeding, or for protection. Predators on Primnoa polyps included sea stars, nudibranchs, and snails. Sea stars were the main predators, consuming 45% and 34% of the polyps at two sites. Suspension-feeders included crinoids, basket stars, anemones, and sponges. Most suspension-feeders observed at depths >300 meters were associated with Primnoa. Protection-seekers included rockfishes, crabs, and shrimps. Individuals of six rockfish species were either beneath, among, or above Primnoa. Shrimp were among the coral polyps, and a pair of mating king crabs were observed beneath a Primnoa colony.