Gaidropsarus mauritanicus sp. nov. is described from one specimen collected using a grab sample from the Tanoûdêrt Canyon (ca. 20° N) off Mauritania at a depth of 595 m. The new species was further observed during eight remotely operated vehicle (ROV) dives along the Mauritanian slope southwards down to the Tiguent Coral Mound Complex (~17° N) in a bathymetric range between 613 and 416 m. It can be distinguished from congeners by a combination of characteristics, including large eyes (38.1% head length [HL]), large head (25.8% standard length [SL]), elongated pelvic fins (35.7% SL), low number of vertebrae (44), and coloration (pinkish with a dorsal darker brownish hue and bright blotches along the dorsal-fin base). A species-delimitation analysis performed with available cytochrome c oxidase subunit 1 (COI) sequences affiliated to the genus Gaidropsarus additionally supported the validity of the new species. Video analyses showed a deep-water coral-associated and protection-seeking behavior, which may explain why the species has remained undescribed until now. Additional ROV footage from separate deep-water coral sites in the North Atlantic and Mediterranean Sea further highlights the ecological behavior and hidden diversity of bathyal three-bearded rocklings. Here, we additionally discuss the biogeographical distribution of all genetically verified Gaidropsarus spp. in combination with genetic data and morphological characters. G. mauritanicus sp. nov. is closely related to a species from Tasmania (43° S), a geographical point furthest among the studied samples, which may hint to an important influence of (paleo-) oceanography on the distributions of Gaidropsarus species.

Swiftia Duchassaing & Michelotti, 1864, is often found sparse in the NE Atlantic Ocean and Mediterranean Sea. When the cruise MSM 16/3 “PHAETON” filmed the upper bathyal off Mauritania in 2010, the first dense populations dominated by Swiftia were discovered in the NE Atlantic Ocean, co-occurring with the framework-forming scleractinians Desmophyllum pertusum (Linnaeus, 1758) and Madrepora oculata Linnaeus, 1758. Remotely operated vehicle (ROV) video annotation from two canyons and two coral mounds considered Swiftia phaeton Sampaio, Beuck & Freiwald, 2022 presence, size class and abundance as well as substrate and geomorphology of the seafloor. Coral gardens definition included abundance and size of the species. Dense and very dense mono- and multispecific coral gardens dominated by S. phaeton were mapped between 20°24′N and 17°54′N in 470–640 m depth. The resilience of these coral gardens off Mauritania is mainly linked to the presence of hard substrate available to settle and to the exposition of currents rich in food. Still, these ecosystems are located inside a hydrocarbon exploration area off Mauritania and where fisheries occur since the 1960s. Sedimentation plumes caused by both activities can travel and impact on settlement, development, and survival of these populations. Hence, these vulnerable “oases” should be protected.

128 129The Central and South Atlantic represents a vast ocean area and is home to a diverse range of ecosystems and species. Nevertheless, and similar to the rest of the global south, the area is comparatively understudied yet exposed to increasing levels of multisectoral pressures. To counteract this, the level of scientific exploration in the Central and South Atlantic has increased in recent years and will likely continue to do so within the context of the United Nations (UN) Decade of Ocean Science for Sustainable Development. Here, we compile the literature to investigate the distribution of previous scientific exploration of offshore (30 m+) ecosystems in the Central and South Atlantic, both within and beyond national jurisdiction, allowing us to synthesise overall patterns of biodiversity. Furthermore, through the lens of sustainable management, we have reviewed the existing anthropogenic activities and associated management measures relevant to the region. Through this exercise, we have identified key knowledge gaps and undersampled regions that represent priority areas for future research and commented on how these may be best incorporated into, or enhanced through, future management measures such as those in discussion at the UN Biodiversity Beyond National Jurisdiction negotiations. This review represents a comprehensive summary for scientists and managers alike looking to understand the key topographical, biological, and legislative features of the Central and South Atlantic.

Commission on Protected Areas and National Geographic Explorer.His main scientific research is about corals and benthic habitats, with particular reference to taxonomy (order Antipatharia, Alcyonacea and Pennatulacea), biodiversity, and population structures.He uses submersibles and remotely operated vehicles for deep-sea explorations, as well as data collected during fishing operations.He also studies the effects of anthropogenic impacts on coral populations.In the course of his work, Dr. Chimienti has discovered some spectacular mesophotic and deep coral habitats in different areas of the world, described new species and participated in the process of protecting some of

Three species of the genus Swiftia are known for the NE Atlantic Ocean and Mediterranean Sea. Remotely-operated vehicle (ROV) surveys and sampling on board RV Maria S. Merian during cruise MSM 16/3 'PHAETON' in 2010 provided footage and specimens of octocorals off Mauritania. Micro-computed tomography (micro-CT) reveals, for the first time in taxonomy of octocorals, the three-dimensional arrangement of the sclerites in a polyp. Swiftiaphaeton sp. nov. is described for the continental slope off Mauritania. This azooxanthellate octocoral is distinctive from NE Atlantic and Mediterranean congenerics by the dark red colour of the colonies (including the polyps), the presence of a layer of rod sclerites on top of the polyp mounds, and different sizes of polyps and sclerites. Using micro-CT has allowed the observation and imaging of a layer of sclerites that is distinct from other species of the same genus. ROV images revealed live records of S.phaeton sp. nov. in submarine canyons and on cold-water coral mounds in the upper-bathyal off Mauritania (396-639 m depth), mainly attached to dead coral, coral rubble, or rocks. The new species represents an extension of the genus distribution to the tropical latitudes (17°07'N and 20°14'N) of the NE Atlantic Ocean.

Here we present a comprehensive attempt to correlate aragonitic Na∕Ca ratios from Desmophyllum pertusum (formerly known as Lophelia pertusa), Madrepora oculata and a caryophylliid cold-water coral (CWC) species with different seawater parameters such as temperature, salinity and pH. Living CWC specimens were collected from 16 different locations and analyzed for their Na∕Ca ratios using solution-based inductively coupled plasma-optical emission spectrometry (ICP-OES) measurements. The results reveal no apparent correlation with salinity (30.1–40.57 g kg−1) but a significant inverse correlation with temperature (-0.31±0.04 mmolmol-1∘C-1). Other marine aragonitic organisms such as Mytilus edulis (inner aragonitic shell portion) and Porites sp. exhibit similar results highlighting the consistency of the calculated CWC regressions. Corresponding Na∕Mg ratios show a similar temperature sensitivity to Na∕Ca ratios, but the combination of two ratios appears to reduce the impact of vital effects and domain-dependent geochemical variation. The high degree of scatter and elemental heterogeneities between the different skeletal features in both Na∕Ca and Na∕Mg, however, limit the use of these ratios as a proxy and/or make a high number of samples necessary. Additionally, we explore two models to explain the observed temperature sensitivity of Na∕Ca ratios for an open and semi-enclosed calcifying space based on temperature-sensitive Na- and Ca-pumping enzymes and transport proteins that change the composition of the calcifying fluid and consequently the skeletal Na∕Ca ratio.

Three species in the gastropod genus Calliostoma are confirmed as living in Deep-Water Coral (DWC) habitats in the NE Atlantic Ocean: Calliostoma bullatum (Philippi, 1844), C. maurolici (Seguenza. 1876) and C. leptophyma Dautzenberg & Fischer, 1896. Up to now, C. bullatum was only known as fossil from Early to Mid-Pleistocene outcrops in DWC-related habitats in southern Italy; our study confirmed its living presence in DWC off Mauritania. A discussion is provided on the distribution of DWC-related calliostomatids in the NE Atlantic and the Mediterranean Sea from the Pleistocene to the present.

Nicolai Schleinkofer, Jacek Raddatz, André Freiwald, David Evans, Lydia Beuck, 3 Andres Rüggeberg, Volker Liebetrau 4 1Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, 60438 Frankfurt am Main, 5 Germany 6 2Frankfurt Isotope and Element Research Center (FIERCE), Goethe University Frankfurt, 7 Altenhöferallee 1, 60438 Frankfurt am Main, Germany 8 3Senckenberg am M0eer, Marine Research Department, Südstrand 40, 26382 Wilhelmshaven, 9 Germany 10 4MARUM (Zentrum für Marine Umweltwissenschaften), Bremen University, Leobener Str. 8, 11 28359 Bremen, Germany 12 5Department of Geosciences, Faculty of Science and Medicine, University of Fribourg, Chemin du 13 Musée 6, CH-1700 Fribourg, Switzerland 14 6GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, D-24148 Kiel, Germany 15 16

Four cribrilinid bryozoans associated with deep-water corals (578-682 m depth) from the Great Bahama Bank slope, are described, two of them are new. The generic allocation of some species prompted us to raise the subgenera Puellina, Cribrilaria, and Glabrilaria to genus rank. The new combination Cribrilaria saginata (Winston, 2005) n. comb, is proposed. Genus Glabrilaria is reported from the NW Atlantic for the first time based on the description of Glabrilaria hirsuta Rosso n. sp. and Glabrilaria polita Rosso n. sp. The new genus Teresaspis Rosso n. gen. is erected, and Teresaspis lineata (Canu & Bassler, 1928) n. comb, is proposed as its type species. The new genus Harmelinius Rosso n. gen. is erected for Cribrilina uniserialis (Harmelin, 1978). Both genera have uniserial colonies formed by slightly caudate zooids with extensive gymnocyst and a frontal shield of flattened costae. Teresaspis lineata n. comb., however, has costae with pelmatidia that are connected by few intercostal bridges and separated by intercostal spaces, four orificial costa-like processes with the proximal pair arching above the orifice, hyperstomial acleithral ovicells with a pseudoporous ooecium formed by the distal zooid or a kenozooid, two types of kenozooids (large with costate frontal shield and small with smooth shield and central opesia), and an ancestrula with costate frontal shield. Avicularia are apparently absent in this species. In contrast, the type species of Harmelinius Rosso n. gen. has costae lacking pelmatidia and which are separated by slit-like intercostal spaces. The hyperstomial cleithral ovicells have smooth ooecia with a median suture and without pseudopores, and are formed by a distal kenozooid associated with a small avicularium. Additional paired oral avicularia are occasionally present, as are large kenozooids with a central opesia. Oral spines or spine-like processes are absent. Taxonomy of the above reported cribrilinid genera is discussed in detail together with the geographic distribution of all mentioned taxa.

The largest coherent cold-water coral (CWC) mound province in the Atlantic Ocean exists along the Mauritanian margin, where up to 100 m high mounds extend over a distance of similar to 400 km, arranged in two slope-parallel chains in 400-550 m water depth. Additionally, CWCs are present in the numerous submarine canyons with isolated coral mounds being developed on some canyon flanks. Seventy-seven Uranium-series coral ages were assessed to elucidate the timing of CWC colonisation and coral mound development along the Mauritanian margin for the last similar to 120,000 years. Our results show that CWCs were present on the mounds during the Last Interglacial, though in low numbers corresponding to coral mound aggradation rates of 16 cm kyr(-1). Most prolific periods for CWC growth are identified for the last glacial and deglaciation, resulting in enhanced mound aggradation (>1000 cm kyr(-1)), before mound formation stagnated along the entire margin with the onset of the Holocene. Until today, the Mauritanian mounds are in a dormant state with only scarce CWC growth. In the canyons, live CWCs are abundant since the Late Holocene at least. Thus, the canyons may serve as a refuge to CWCs potentially enabling the observed modest re-colonisation pulse on the mounds along the open slope. The timing and rate of the pre-Holocene coral mound aggradation, and the cessation of mound formation varied between the individual mounds, which was likely the consequence of vertical/lateral changes in water mass structure that placed the mounds near or out of oxygen-depleted waters, respectively. (C) 2018 The Authors. Published by Elsevier Ltd.

During a deep-water expedition to the Red Sea in 2013, an unusual specimen of squat lobster belonging to the genus Munida was collected off Thuwal, Saudi Arabia, at a depth of 320 m. This specimen is unique in having the pterygostomial flap visible from the dorsal side, the feature linking it to two eastern Pacific species, M. bapensis Hendrickx, 2000 and M. macrobrachia Hendrickx, 2003. The new species (M. tuerkayi) is readily distinguished from the eastern Pacific species by having the gastric region with numerous instead of less numerous spines, by having sternite 7 with three distinct carinae on each side, and by having the antennular basal article with two distal spines subequal instead of different in size. Munida tuerkayi was found associated with live colonies of the scleractinian coral Eguchipsammia fistula (Alcock, 1902).

Cold-water corals (CWC) can form complex structures which provide refuge, nursery grounds and physical support for a diversity of other living organisms. However, irrespectively from such ecological significance, CWCs are still vulnerable to human pressures such as fishing, pollution, ocean acidification and global warming Providing coherent and representative conservation of vulnerable marine ecosystems including CWCs is one of the aims of the Marine Protected Areas networks being implemented across European seas and oceans under the EC Habitats Directive, the Marine Strategy Framework Directive and the OSPAR Convention. In order to adequately represent ecosystem diversity, these initiatives require a standardised habitat classification that organises the variety of biological assemblages and provides consistent and functional criteria to map them across European Seas. One such classification system, EUNIS, enables a broad level classification of the deep sea based on abiotic and geomorphological features. More detailed lower biotope-related levels are currently underdeveloped, particularly with regards to deep-water habitats ( > 200 m depth). This paper proposes a hierarchical CWC biotope classification scheme that could be incorporated by existing classification schemes such as EUNIS. The scheme was developed within the EU FP7 project CoraIFISH to capture the variability of CWC habitats identified using a wealth of seafloor imagery datasets from across the Northeast Atlantic and Mediterranean. Depending on the resolution of the imagery being interpreted, this hierarchical scheme allows data to be recorded from broad CWC biotope categories down to detailed taxonomy-based levels, thereby providing a flexible yet valuable information level for management. The CWC biotope classification scheme identifies 81 biotopes and highlights the limitations of the classification framework and guidance provided by EUNIS, the EC Habitats Directive, OSPAR and FAO; which largely underrepresent CWC habitats.

In this study, we describe a new species of cladorhizid sponge, which shows a very peculiar mode of life: It always occurs in association with the scleractinian cold-water corals Lophelia pertusa and Madrepora oculata. Although the sponge lives in nutrient-rich areas, we document its carnivorous feeding behavior. The identity of the new species was verified using molecular markers: the species is very closely related to the North-Atlantic Cladorhiza abyssicola, but it differs distinctly, and forms a monophyletic clade. The two species might be considered very close relatives, probably sister species deriving from a common ancestor.

During two cruises to the Gulf of Mexico and Caribbean Sea, some specimens of squat lobsters belonging to the genus Munidopsis Whiteaves, 1874 (family Munidopsidae Ortmann, 1898) were collected. The present collection comprises five species, where two are considered as new species: M. karukera, closely related to M. ariadne Macpherson, 2011, from the Mediterranean Sea; and M. tuerkayi, which resembles M. kareenae Ahyong, 2013, from New Zealand. The specimens were caught at six stations between 522 and 1162 m; some were associated with live cold-water corals, such as Lophelia pertusa (Linnaeus, 1758), Enallopsammia profunda (Pourtalès, 1867) and Candidella imbricata (Johnson, 1862).

Valuable megafaunal sessile assemblages in the southern Adriatic basin present a western–eastern asymmetric distribution. This is particularly evident when considering cold-water coral (CWC) communities, with most diverse and abundant live corals to be found along the western side. On the contrary, only spotty occurrences are documented in the eastern side and at times only in a sub-fossil state. We hypothesize that this asymmetry might derive from differential exposure of the Adriatic floor to polarized hydrological processes. In such a perspective, vigorous albeit a-periodical flushing of deep-sea bottoms at times of cascading processes could be beneficial to sessile deep-sea benthic communities by reinforcing the North Adriatic Dense Water (NAdDW), contrasting excess silting and by enhancing the trophic web. Although no experimental evidence has been yet produced to test this hypothesis, it gains some support by the observation that CWC are flourishing in the general area of the Bari Canyon and adjacent bottoms flushed by dense shelf water (DSW) cascading while they are much less developed on the basin's opposite side, unaffected by this phenomenon.