Benthic megafauna of the western Clarion-Clipperton Zone, Pacific Ocean Author Bribiesca-Contreras, Guadalupe https://orcid.org/0000-0001-8163-8724 Life Sciences Department, Natural History Museum, London, UK l.bribiesca-contreras@nhm.ac.uk Author Dahlgren, Thomas G. https://orcid.org/0000-0001-6854-2031 Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden & Norwegian Research Centre, NORCE, Bergen, Norway Author Amon, Diva J. SpeSeas, D'Abadie, Trinidad and Tobago Author Cairns, Stephen https://orcid.org/0000-0001-7209-9271 Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, D. C., USA Author Drennan, Regan https://orcid.org/0000-0003-0137-5464 National Oceanography Centre, Southampton, UK Author Durden, Jennifer M. https://orcid.org/0000-0002-6529-9109 UMR ISYEB, Department Origines et Evolution, Museum national d'Histoire Naturelle, Paris, France Author Eleaume, Marc P. Collections & Research, Western Australia Museum, Perth, Australia Author Hosie, Andrew M. https://orcid.org/0000-0002-5683-662X Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia Author Kremenetskaia, Antonina https://orcid.org/0000-0001-8851-3318 School of Biological and Marine Sciences, University of Plymouth, Plymouth, UK Author McQuaid, Kirsty https://orcid.org/0000-0002-0395-8332 Museums Victoria, Melbourne, Australia Author O'Hara, Timothy D. Department of Oceanography, University of Hawai'i at Manoa, Honolulu, USA Author Rabone, Muriel https://orcid.org/0000-0002-8351-2313 National Oceanography Centre, Southampton, UK Author Simon-Lledo, Erik UMR ISYEB, Department Origines et Evolution, Museum national d'Histoire Naturelle, Paris, France Author Smith, Craig R. https://orcid.org/0000-0002-3976-0889 School of Life Sciences, University of Hawai'i at Manoa, Honolulu, USA Author Watling, Les https://orcid.org/0000-0002-6901-1168 School of Life Sciences, University of Hawai'i at Manoa, Honolulu, USA Author Wiklund, Helena https://orcid.org/0000-0002-8252-3504 Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden Author Glover, Adrian G. https://orcid.org/0000-0002-9489-074X National Oceanography Centre, Southampton, UK text ZooKeys 2022 2022-07-18 1113 1 110 http://dx.doi.org/10.3897/zookeys.1113.82172 journal article http://dx.doi.org/10.3897/zookeys.1113.82172 1313-2970-1113-1 EB46BF265F2E51B3A83799886C5F084A Oneirophanta stet. CCZ_100 Fig. 40 Material. Clarion-Clipperton Zone • 1 specimen ; APEI 4; 7.2647°N , 149.774°W ; 3550 m deep; 03 Jun. 2018 ; Smith & Durden leg.; GenBank : ON400706 (COI), ON406643 (18S), ON406620 (16S); NHMUK 2022.84; Voucher code: CCZ_100 . Description. Single specimen; colouration of live specimen is beige, spotted with light brown and yellow on dorsal surface (Fig. 40A, C, D ), and lighter on ventral surface, with suckers on tube feet and tentacles being dark brown (Fig. 40D ). Body cylindrical, ~ 33 cm long and 8.8 cm wide; mouth anteroventral, anus posteroventral. Tentacles partly retracted. Papillae arranged in one or two rows along the dorsal radii, and in a single row along the ventrolateral radii above the tube feet. Tube feet ~ 50 pairs, arranged in two or three rows on each ventrolateral ambulacrum; few tube feet located along mid-ventral ambulacrum, among them two tube feet, one placed approx. half the body length and the other approx. three quarter of the body length; and few smaller feet close to anus. Dorsal ossicles spatulated crosses, crosses with open ramifications, and small irregular perforated plates; ventral ossicles crosses with open ramifications of different stage of development. Figure 40. Oneirophanta stet. CCZ_100 A dorsal view of specimen before preservation B in situ image C ventral view D dorsal ossicles E ventral ossicles. Scale bars: 2 cm ( A, C ); 5 cm ( B ); 200 μm ( D ); 100 μm ( E ). Image attribution: Wiklund, Durden, Drennan, and McQuaid ( A, C ); Durden and Smith ( B ); Kremenetskaia ( D, E ). Remarks. Closest match for COI and 16S sequences is to Oneirophanta setigera (Ludwig, 1893) (86.7% and 96.3%, respectively). In the phylogenetic tree, it is recovered in a well-supported clade representing the family Deimatidae , including Oneirophanta (Fig. 34 ). According to the external morphology Oneirophanta sp. CCZ_100 differs from Oneirophanta mutabilis mutabilis Theel , 1879, O. mutabilis affinis Ludwig, 1893 and O. conservata Koehler & Vaney, 1905 in high number of tube feet arranged in two or three rows and by absence of large, perforated plates on dorsum. It differs from O. setigera in high number of tube feet arranged in two or three rows and by presence of small, perforated plates and bigger perforations on spatulated crosses. Ecology. The specimen was found on the sediment seafloor of a seamount on APEI 4 at 3550 m depth. Comparison with image-based catalogue. No exactly similar Deimatidae morphotypes have been so far catalogued from seabed imagery collected in the eastern CCZ nor in abyssal areas of the Kiribati EEZ. Consequently, the in situ image of CCZ_100 was catalogued as a new morphotype (i.e., Oneirophanta sp. indet., HOL_063). However, HOL_063 could be potentially confused with a similar shaped Deimatidae morphotype (e.g., Deimatidae gen. indet., HOL_062; also beige, cylindrical, with conspicuous projections on the dorsal surface arranged in four rows) found in the eastern CCZ (e.g., Amon et al. 2017b ), with more abundant -though slightly thinner- projections, that may be difficult to distinguish in vertically facing images.