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 Peniagone leander Pawson & Foell, 1986 Fig. 46 Material. Clarion-Clipperton Zone • 1 specimen ; APEI 7; 5.1042°N , 141.8861°W ; 4860 m deep; 25 May. 2018 ; Smith & Durden leg.; GenBank : ON400681 (COI), ON406621 (16S); NHMUK 2022.61; Voucher code: CCZ_018 . Description. Single specimen observed swimming (Fig. 46A ). Specimen was severely damaged during collection, with only a few tentacles recovered, and hence description of morphological characters is based on in situ images. Body ovoid, slightly> 2 x as long as it is wide. Velum composed of two pairs of fully fused papillae. Tube feet four pairs; three posteriormost pairs fused together forming a posterior swimming lobe; tube feet from the anteriormost pair very short. Figure 46. Peniagone leander Pawson & Foell, 1986. Specimen CCZ_018: A, B in situ images C tentacle ossicles. Scale bars: 100 µm ( C ). Image attribution: Durden and Smith ( A, B ); Bribiesca-Contreras ( C ). Remarks. The specimen collected during the DeepCCZ expedition was recovered in bits, so no morphological features can be distinguished. Only four reddish orange tentacles were recovered, which are embedded in a transparent skin where ossicles are evident. However, P. leander is one of the few species that can be identified from images. The external morphological characters evident in in situ images from the CCZ specimen are in accordance with the species description. The species was originally described from in situ images and video footage collected across the eastern CCZ ( Pawson and Foell 1986 ) and subsequently observed in the area (e.g., Amon et al. 2017b ). In the phylogenetic tree, the CCZ specimen was recovered in a well-supported clade with other species of Peniagone (Fig. 34 ). It was recovered together with a sequence of P. leander , which was recently rediscovered and collected for the first time in the Mariana Trench ( Gong et al. 2020 ), both close to P. diaphana as reported by Gong et al. (2020) . The 16S sequence of the CCZ specimen is similar (K2P distance = 2%) to the only available sequence from P. leander , but no COI sequence was made available. Our COI sequence is> 12% divergent (K2P distance) from other species within the genus. The COI gene seems to be highly divergent between species in this genus. Using the data provided in Kremenetskaia et al. (2021) and including the CCZ sequence of P. leander , COI mean interspecific divergence in the genus is 15.9% (min = 2.5% and max = 22.7%), with our sequence of P. leander being 14.5%-21.2% divergent from other species within the genus. Intraspecific divergence for species in the genus was estimated between 0.9%-3.0%. Ecology. The specimen was found swimming near the sediment surface on an abyssal plain in APEI 7 at 4860 m depth. Comparison with image-based catalogue. Peniagone leander (HOL_028) has been commonly encountered in seabed image surveys conducted across the eastern CCZ (e.g., Amon et al. 2017b ) and in abyssal areas of the Kiribati EEZ, usually swimming above the seabed but sometimes creeping on it. Body colour appears to be variable; bright red, semi-transparent, purplish, and whitish HOL_028 specimens have been encountered in seabed image surveys across the CCZ.