Records of Primnoidae (Cnidaria, Anthozoa, Octocorallia) from Costa Rican Pacific Seamounts

Nine species of primnoid octocorals are reported from seamounts off the Pacific coast of Costa Rica, eight of them representing new records for the country. The specimens were primarily collected during five oceanographic expeditions conducted between 2017 and 2019, and in 2023, at depths ranging from 519 to 3031 m using the vessels: RV Atlantis, with HOV Alvin, RV Falkor and RV Falkor (too), with the ROV SuBastian. The species are identified and illustrated with in situ photographs obtained by the ROV. Except for the genus Calyptrophora all samples were identified at the species level. Phylogenetic relationships of the Calyptrophora specimens were assessed using ultraconserved elements and exon loci and uncovered the presence of a cryptic species within the Calyptrophora bayeri complex. This research provides valuable insights into the biodiversity of Costa Rica deep waters