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In this report, we analyse the benthic hydroids collected on the Vema and Valdivia seamounts during a survey conducted in 2015 in the SEAFO Convention Area, focused on mapping and analysing the occurrence and abundance of benthopelagic fish and vulnerable marine ecosystem (VMEs) indicators on selected Southeast Atlantic seamounts. A total of 27 hydroid species were identified, of which 22 belong to Leptothecata and only five to Anthoathecata. Monostaechoides gen. nov. was erected within the family Halopterididae to accommodate Plumularia providentiae Jarvis, 1922, and a new species, Monotheca bergstadi sp. nov., is also described. Campanularia africana is recorded for the first time from the Atlantic Ocean, and the Northeast Atlantic species Amphinema biscayana, Stegopoma giganteum and Clytia gigantea are also recorded from the South Atlantic. Three species were identified to the genus level only, due to the absence of their gonosomes. None of the reported species are endemic, and the hydroid community is clearly dominated by species with a wide geographical distribution in the three major oceans. Only Monotheca bergstadi sp. nov. presently has its distribution restricted to the Vema Seamount and the South African coast.

Agassiz, L. (1862) Contributions to the natural history of the United States of America. Vol. 4. Little Brown, Boston, 380 pp.Aguirrezabalaga, F., Altuna, A., Borja, A., Feliu, J., GarcíaCarrascosa, A.M., Romero, A., San Vicente, C., Torres-Gómez-de-Cádiz, J.A., Uriz, M.J. & Ibánez, M. (1984) Contribución al conocimiento de la fauna marina de la costa Vasca. Π. Lurralde, Investigación y espacio, 1984, pp. 83–133.Alder, J. (1856) A notice of some new genera and species of British hydroid zoophytes. Annals and Magazine of Natural History, Series 2, 18, 353–362. https://doi.org/10.1080/00222935608697652Allman, G.J. (1873) Interim report on the hydroids collected by L.F. de Pourtalès during the Gulf Stream exploration of United States coast survey. Bulletin of the Museum of Comparative Zoology at Harvard College, 3 (7), 185–186.Allman, G.J. (1874) Report on the Hydroida collected during the expeditions of H.M.S. ‘Porcupine.’ Transactions of the Zoological Society of London, 8, 469–481. https://doi.org/10.1111/j.1096-3642.1874.tb00566.xAllman, G.J. (1877) Report on the Hydroida collected during the exploration of the Gulf Stream by L.F. de Pourtalès, assistant United States Coast Survey. Memoirs of the Museum of Comparative Zoology at Harvard College, 5 (2), 1–66. https://doi.org/10.5962/bhl.title.15852Allman, G.J. (1883) Report on the Hydroida dredged by H.M.S. Challenger during the years 1873–76. I. Plumularidae. Report of the Scientific Results of the Voyage of H.M.S. Challenger 1873–1876, 1–55, pls. 1–20. https://doi.org/10.5962/bhl.title.11299Altuna, A. (2012) New records of bathyal Leptolida (Cnidaria: Hydrozoa: Leptothecata) from the Bay of Biscay and the northwestern Iberian Peninsula (northeastern Atlantic). Zootaxa, 3565 (1), 1–17. https://doi.org/10.11646/zootaxa.3565.1.1Altuna Prados, A. & Álvarez Claudio, C. (1994) El género Zygophylax Quelch, 1885 (Cnidaria, Hydrozoa) en el Golfo de Vizcaya. Miscel.lània Zoològica, 17, 1−16.Alvarez Claudio, M.C. (1993) Hidrozoos bentonicos y Catálogo de Antozoos de la Plataforma y Talud Continentales de la costa central de Asturias. Tesis de Licenciatura, Universidad de Oviedo, Oviedo, Asturias, 458 pp.Alvarez Claudio, M.C. (1995) Some records of the superfamily Plumularioidea L. Agassiz, 1862 (Cnidaria, Hydrozoa) from the Bay of Biscay. Miscel·lània Zoològica, 18, 9−20.Ansín Agís, J. (1992) Hidrozoos de la Ría de Vigo. Tesis de Licenciatura, Universidad de Vigo, Ourense, Galicia, 282 pp.Ansín Agís, J. (1998) Plumularioidea (Cnidaria, Hydrozoa) recolectados por las expediciones holandesas “CANCAP” en el Atlántico nor-oriental. Tesis Doctoral, Universidade de Vigo, Vigo, Galicia, 675 pp. Ansín Agís, J., Ramil, F. & Vervoort, W. (2001) Atlantic Leptolida (Hydrozoa, Cnidaria) of the families Aglaopheniidae, Halopterididae, Kirchenpaueriidae and Plumulariidae collected during the CANCAP and Mauritania-II expeditions of the National Museum of Natural History, Leiden, The Netherlands. Zoologische verhandelingen, Leiden, 333, 1–268.Ansín Agís, J., Vervoort, W. & Ramil, F. (2014) Hydroids of the families Kirchenpaueriidae Stechow, 1921 and Plumulariidae McCrady, 1859 (Cnidaria, Hydrozoa) collected in the Western Pacific Ocean by various French Expeditions. Zoosystema, 36, 789–840. https://doi.org/10.5252/z2014n4a6Arévalo y Carretero, C. (1906) Contribución al estudio de los Hidrozoarios españoles existentes en la Estación de Biología marítima de Santander. Memorias de la Real Sociedad Española de Historia Natural, 4 (3), 79–109.Avila, S.P. & Malaquias, M.A.E. (2003) Biogeographical relationships of the molluscan fauna of the Ormonde Seamount (Gorringe Bank, Northeast Atlantic Ocean). Journal of Molluscan Studies, 69, 145–150. https://doi.org/10.1093/mollus/69.2.145Bale, W.M. (1915) Report on the Hydroida collected in the Great Australian Bight and other localities. Part III. Fish. Zool. (biol) Biological Results of the Fishing Experiments Carried on by the F.I.S. “Endeavour”, 1909–14, 3 (5), 304–307.Bedot, M. (1916) Sur le genre Kirchenpaueria. Revue Suisse de Zoologie, 24 (11), 637–648.Bedot, M. (1917) Le genre Nemertesia. Mémoire de la Société de Physique et d’Histoire Naturelle de Genève, 39 (1), 15–52.Bedot, M. (1921a) Notes systématiques sur les plumularides. 2me partie. Revue Suisse de Zoologie, 29 (1), 1–40. https://doi.org/10.5962/bhl.part.84689Bedot, M. (1921b) Hydroïdes provenant des campagnes des yachts Hirondelle et Princesse–Alice (1887–1912). I. Plumulariidae. Résultats des Campagnes scientifiques accomplies sur son yacht par le Prince Albert Ier de Monaco, 60, 1–73.Bedot, M. (1923) Notes systématiques sur les plumularides. 3me partie. Revue Suisse de Zoologie, 30 (7), 213–243.Billard, A. (1901) Note sur l’Antennularia antennina Lin. et sur l’A. perrieri n. sp. Bulletin du Museìum national d’histoire naturelle, Paris, 7, 68–75.Billard, A. (1904) Contribution à l’étude des Hydroïdes (multiplication, regeneration, greffes, variations). Annales des sciences naturelles, Zoologie, Series 8, 20, 1–251.Billard, A (1906a) Hydroïdes. In: Mission des pêcheries de la côte occidental d’Afrique, III. Actes de la Société Linnéenne de Bordeaux, 61, 69–76.Billard, A. (1906b) Hydroïdes. In: Expéditions scientifiques du “Travailleur” et du “Talisman” pendant les années 1880, 1881, 1882, 1883, etc. Masson & Cie., Paris, pp. 153–243.Billard, A. (1906c) Note sur les Hydroïdes du Travailleur et du Talisman. Bulletin du Museìum national d’histoire naturelle, 12 (5), 329–334.Billard, A. (1931) Hydroïdes de Mauritanie. Bulletin du Muséum national d’histoire naturelle, Series 2, 3 (7), 673–678.Billard, A. (1934) Note sur quelques hydroïdes du Maroc. Bulletin de la Société Zoologique de France, 59, 227–231. Boero, F. & Bouillon, J. (1993) Zoogeography and life cycle patterns of Mediterranean hydromedusae (Cnidaria). Biological Journal of the Linnean Society, 48, 239–266. https://doi.org/10.1111/j.1095-8312.1993.tb00890.xBoero, F. & Fresi, E. (1986) Zonation and evolution of a rocky bottom hydroid community. Marine Ecology, 7 (2), 123–150. https://doi.org/10.1111/j.1439-0485.1986.tb00152.xBouillon, J. (1984) Révision de la famille des Phialuciidae (Kramp, 1955) (Leptomedusae, Hydrozoa, Cnidaria), avec un essai de classification des Thecatae-Leptomedusae. Indo-Malayan Zoology, 1, 1–24.Bouillon, J., Massin, C. & Kresevic, R. (1995) Hydroidomedusae de l’Institut royal des Sciences naturelles de Belgique. Documents de travail de l’Institut royal des Sciences naturelles de Belgique, 78, 3–106.Bouillon, J., Medel, M.D., Pagès, F., Gili, J.M., Boero, F. & Gravili, C. (2004) Fauna of the Mediterranean Hydrozoa. Scientia Marina, 68 (2), 5–438. https://doi.org/10.3989/scimar.2004.68s25Bouillon, J., Gravili, C., Pagès, F., Gili, J.M. & Boero, F. (2006) An introduction to Hydrozoa. Editions du Muséum, Paris, 591 pp.Broch, H. (1913) Hydroida from the “Michael Sars” North Atlantic Deep-Sea Expedition 1910. In: Report on the scientific results of the “Michael Sars” north Atlantic deep-sea expedition 1910 3(1) Zoology, 1–18.Broch, H. (1914) Hydrozoa benthonica. In: Michaelsen, W. (Ed.), Beiträge zur Kenntnis der Meeresfauna Westafrikas. Vol. 1. Friederichsen, Hamburg, pp. 19–50.Browne, E.T. (1907) The Hydroida collected by the “Huxley” from the North Side of the Bay of Biscay in August, 1906. Journal of the Marine Biological Association of the United Kingdom, 8, 15–37. https://doi.org/10.1017/S002531540004371XBuchanan, J.B. (1957) The hydroid fauna of the Gold Coast. Revue de Zoologie et de Botanique Africaines, 56 (3–4), 349–372.Burdon-Jones, C. & Tambs-Lyche, H. (1960) Observations on the fauna of the North Brattholmen stone-coral reef near Bergen. Årbok for Universitetet i Bergen, Matematisk–naturvitenskapling, 1960 (4), 1–24.Cairns, S.D. & Chapman, R.E. (2001) Biogeographic affinities of the North Atlantic deep-water Scleractinia. In: Willison, J.H.M., Hall, J., Gass, S.E., Kenchington, E.L.R., Butler, M. & Doherty, P. (Eds.), Proceedings of the First International Sympo-sium on Deep-Sea Corals. Ecology Action Centre, Halifax, pp. 30–57Calder, D.R. (1988) Shallow-water hydroids of Bermuda: the Athecatae. Royal Ontario Museum, Life Sciences Contributions, 148, 1–107. https://doi.org/10.5962/bhl.title.52225Calder, D.R. (1991) Shallow-water hydroids of Bermuda. The Thecatae, exclusive of Plumularioidea. Royal Ontario Museum, Life Sciences Contributions, 154, 1–140.Calder, D.R. (1997) Shallow-water hydroids of Bermuda: superfamily Plumularioidea. Royal Ontario Museum, Life Sciences Contributions, 161, 1–85.Calder, D.R. (1998) Hydroid diversity and species composition along a gradient from shallow waters to deep sea around Bermuda. Deep-Sea Research I, 45, 1843–1860. https://doi.org/10.1016/S0967-0637(98)00044-2Calder, D.R. (2012) On a collection of hydroids (Cnidaria, Hydrozoa, Hydroidolina) from the west coast of Sweden, with a checklist of species from the region. Zootaxa, 3171 (1), 1–77. https://doi.org/10.11646/zootaxa.3171.1.1Calder, D.R. & Vervoort, W. (1998) Some hydroids (Cnidaria: Hydrozoa) from the Mid-Atlantic Ridge, in the North Atlantic Ocean. Zoologische verhandelingen, Leiden, 319, 1–65.Calero, B., Ramil, F. & Ramos, A. (2017) Echinoderms of the Mauritanian Deep-Sea Waters. In: Ramos, A., Ramil, F. & Sanz, J.L. (Eds.), Deep sea ecosystems off Mauritania: Researching marine biodiversity and habitats in West African Deep-waters. Springer, Dordrecht, pp. 445–480. https://doi.org/10.1007/978-94-024-1023-5_12Castillo, S. (2017) Marine Mollusc (Gastropoda and Bivalvia) from Northwest Africa. Undergraduate dissertation, Universidad de Vigo, Pontevedra, Ourense, Vigo, Galicia, 422 pp.Christiansen, B.O. (1972). The hydroid fauna of the Oslo Fjord in Norway. Norwegian Journal of Zoology, 20, 279–310.Clarke, S.F. (1879) Report on the Hydroida collected during the Exploration of the Gulf Stream of Mexico by Alexander Agassiz, 1877–78. Bulletin of the Museum of Comparative Zoology, 5, 239–252, pls. 1–5.Collins, J.S.H., Ross, A.J., Genzano, G. & Mianzan, H. (2006) Earleria gen. nov. & Gabriella gen. nov., replacement names for Foersteria Arai & Brinckmann-Voss, 1980 (Cnidaria, Hydrozoa, Mitrocomidae) and Foersteria Wehner, 1988 (Crustacea, Decapoda, Prosopidae), junior homonyms of Foersteria Szepligeti, 1896 (Insecta, Hymenoptera, Braconidae). Bulletin of the Mizunami Fossil Museum, 33, 125–126.Cornelius, P.F.S. (1975) A revision of the species of Lafoeidae and Haleciidae (Coelenterata: Hydroida) recorded from Britain and nearby seas. Bulletin of the British Museum (Natural History), Zoology, 28, 375–426.Cornelius, P.F.S. (1979) A revision of species Sertulariidae (Coelenterata: Hydroida) recorded from Britain and nearby seas. Bulletin of the British Museum (Natural History), Zoology Series, 34 (6), 243–321.Cornelius, P.F.S. (1995a) North-West European Thecate Hydroids and their Medusae. Part 1. Part 1. Introduction, Laodiceidae to Haleciidae. Synopses of the British Fauna, New Series, 50, 1–347.Cornelius, P.F.S. (1995b) North-West European Thecate Hydroids and their Medusae. Part 2. Sertulariidae to Campanulariidae. Synopses of the British Fauna, New Series, 50, 1–386.De Matos Pita, S. (2015) Crustáceos Decápodos de aguas profundas de Mauritania (África Noroccidental). Undergraduate dissertation, Universidad de Vigo, Pontevedra, Ourense, Vigo, Galicia, 308 pp.Di Camillo, C.G., Boero, F., Gravili, C., Previati, M., Torsani, F. & Cerrano, C. (2013) Distribution, ecology and morphology of Lytocarpia myriophyllum (Cnidaria: Hydrozoa), a Mediterranean Sea habitat former to protect. Biodiversity and Conservation, 22,773–789. https://doi.org/10.1007/s10531-013-0449-9Dons, C. (1944) Norges korallrev. Det Kongelige Norske Videnskabers Selskabs Forhandlinger, 16, 37–82.Ehrenberg, C.G. (1834) Beiträge zur physiologischen Kenntniss der Corallenthiere im allgemeinen, und besonders des rothen Meeres, nebst einem Versuche zur physiologischen Systematik derselben. Abhandlung der Königlichen Akademie der Wissenschaften, Berlin, 1, 225–380.Eschscholtz, F. (1829) System der Acalephen. Eine ausführliche Beschreibung aller medusenartigen Strahltiere. Ferdinand Dümmler, Berlin, 190 pp. https://doi.org/10.5962/bhl.title.10139Fey, A. (1969) Peuplements sessiles de l’archipel de Glénan. 1.-Inventaire: hydraires. Vie Milieu, 20 (2), 387–414.Fraser, C.M. (1912) Some hydroids of Beaufort, North Carolina. Bulletin of the United States Bureau of Fisheries, 30, 337–387.Fraser, C.M. (1944) Hydroids of the Atlantic coast of North America. The University of Toronto Press, Toronto, 451 pp.Freiwald, A., Fosså, J.H., Grehan, A., Koslow, T. & Roberts, J.M. (2004) Cold-water coral reefs. UNEP-WCMC, Cambridge, Biodiversity Series, 22, 1–84.Freiwald, A., Beuck, L., Lundälv, T. & Wienberg, C. (2012) General morphology and preliminary biological inventory of the Mauritanian cold-water coral habitats. In: Westphal, H., Beuck, L., Braun, S., Freiwald, A., Hanebuth, T., Hetzinger, S., Klicpera, A., Kudrass, H., Lantzsch, H., Lundälv, T., Mateu Vicens, G., Preto, N., Reumont, J.V., Schilling, S., Taviani, M. & Wienberg, C. (Eds.), Report of Cruise Maria S. Merian 16/3—Phaeton—Paleoceanographic and paleo˗climatic record on the Mauritanian shelf. 13 October. 13–20 November 2010. Bremerhaven (Allemagne)˗Mindelo (Cap Verde). Maria S. Merian˗Berichte, Leibniz˗ZMT, Bremen, pp. 28–40.Galea, H.R. (2007) Hydroids and hydromedusae (Cnidaria: Hydrozoa) from the fjords region of southern Chile. Zootaxa, 1597, 1–116.Genzano, G.N. & Zamponi, M.O. (1999) Natural history of Bimeria vestita Wright, 1859 (Hydrozoa, Bougainvilliidae) in the rocky intertal of Mar del Plata (Argentina). Ciencias Marinas, 25, 63–74. https://doi.org/10.7773/cm.v25i1.652Gil, M. (2017) Hydroids (Cnidaria, Hydrozoa) from Northwest Africa. Undergraduate dissertation, Universidad de Vigo, Pontevedra, Ourense, Vigo, Galicia, 458 pp.Gil, M. & Ramil, F. (2017a) Hydrozoans from Mauritanian Deep-Waters. In: Ramos, A., Ramil, F. & Sanz, J.L. (Eds.), Deep sea ecosystems off Mauritania: Researching marine biodiversity and habitats in West African Deep-waters. Springer, Dordrecht, pp. 419–444. https://doi.org/10.1007/978-94-024-1023-5_11Gil, M. & Ramil, F. (2017b) The genus Diphasia L. Agassiz, 1862 (Cnidaria, Hydrozoa) in Northwest Africa. Zootaxa, 4363 (3), 301–349. https://doi.org/10.11646/zootaxa.4363.3.1Gili, J.M., Vervoort, W. & Pagès, F. (1989) Hydroids from the West African coast: Guinea Bissau, Namibia and South Africa. Scientia Marina, 53 (1), 67–112.Gmelin, J.F. (1791) Caroli a Linné, systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima tertia, aucta reformata. Tomus I. Pars 6. G. E. Beer, Lipsiae, 1100 pp. [pp. 3021–4120]Gravili, C., Di Camillo, C.G., Piraino, S. & Boero, F. (2013) Hydrozoan species richness in the Mediterranean Sea: past and present. Marine Ecology, 34, 41–62. https://doi.org/10.1111/maec.12023Gravili, C., De Vito, D., Di Camillo, C.G., Martell, L., Piraino, S. & Boero, F. (2015) The non-Siphonophoran Hydrozoa (Cnidaria) of Salento, Italy with notes on their life-cycles: an illustrated guide. Zootaxa, 3908 (1), 1–187. https://doi.org/10.11646/zootaxa.3908.1.1Gray, J.E. (1848) List of the specimens of British animals in the collection of the British Museum. Part 1. Centroniae or radiated animals. British Museum, London, 173 pp.Hassall, A.H. (1841) Supplement to a catalogue of Irish Zoophytes. Annals of natural history, Series 1, 7 (44), 276–287. https://doi.org/10.1080/03745484109442700Henry, L.A. (2001) Hydroids associated with deep-sea corals in the boreal north-west Atlantic. Journal of the Marine Biological Association of the United Kingdom, 81, 163–164. https://doi.org/10.1017/S0025315401003502Henry, L.A. & Roberts, J.M. (2007) Biodiversity and ecological composition of macrobenthos on cold-water coral mounds and adjacent off-mound habitat in the bathyal Porcupine Seabight, NE Atlantic. Deep Sea Research Part I: Oceanographic Research Papers, 54, 654–672. https://doi.org/10.1016/j.dsr.2007.01.005Henry, L.A. & Roberts, J.M. (2016) Global Biodiversity in Cold-Water Coral Reef Ecosystems. In: Rossi, S., Bramanti, L., Gori, A. & Orejas Saco del Valle, C. (Eds.), Marine Animal Forests. Springer, Cham, pp. 235–256. https://doi.org/10.1007/978-3-319-21012-4_6Henry, L.A., Nizinski, M.S. & Ross, S.W. (2008) Occurrence and biogeography of hydroids (Cnidaria: Hydrozoa) from deep-water coral habitats off the southeastern United States. Deep Sea Research Part I: Oceanographic Research Papers, 55, 788–800. https://doi.org/10.1016/j.dsr.2008.03.002Henry, L.A., Frank, N., Hebbeln, D., Wienberg, C., Robinson, L., Van de Flierdt, T., Dahl, M., Douarin, M., Morrison, C.L., López Correa, M., Rogers, A.D., Ruckelshausen, M. & Roberts, J.M. (2014) Global ocean conveyor lowers extinction risk in the deep sea. Deep Sea Research Part I: Oceanographic Research Papers, 88, 8–16. https://doi.org/10.1016/j.dsr.2014.03.004Hincks, T. (1861) A catalogue of the zoophytes of south Devon and South Cornwall. Annals and Magazine of Natural History, Series 3, 8, 251–262. https://doi.org/10.1080/00222936108697413Hincks, T. (1868) A history of the British hydroid zoophytes. John van Voorst, London, 338 pp. https://doi.org/10.5962/bhl.title.1322Hirohito, E.S. (1995) The hydroids of Sagami Bay II. Thecata. Biological Laboratory Imperial Household, Tokyo, pp. 1–355.Izquierdo, M.S., García-Corrales, P., Bacallado, J.J. (1986b) Contribución al conocimiento de los hidrozoos caliptoblástidos del Archipiélago Canario. Parte II: Plumulariidae. Boletín del Instituto Español de Oceanografía, 3 (2), 49–66.Jäderholm, Ε. (1909) Northern and Arctic invertebrates in the collection of the Swedish State Museum (Riksmuseum). IV. Hydroiden. Kungliga Svenska vetenskapsakademiens handlingar, 45 (1), 1–124.Jäderholm, E. (1919) Zur Kenntnis der Hydroidenfauna Japans. Arkiv för Zoologi, 12 (9), 1–34. Jensen, A. & Frederiksen, R. (1992) The fauna associated with the bank-forming deepwater coral Lophelia pertusa (Scleractinaria) on the Faroe shelf. Sarsia, 77 (1), 53–69. https://doi.org/10.1080/00364827.1992.10413492Jickeli, C.F. (1883) Der Bau der Hydroidpolypen. Morphologisches Jahrbuch, 8, 580–680.Johnston, G. (1833) Illustrations in British zoology. Magazine of natural history and journal of zoology, botany, mineralogy, geology and meteorology, 6, 320–324, 497–499.Johnston, G. (1837) A catalogue of the zoophytes of Berwickshire. Berwickshire Naturalist’s Club Proceedings, 1, 107–108.Johnston, G. (1838) A history of the British zoophytes. W.H. Lizars, Edinburgh, 341 pp. https://doi.org/10.5962/bhl.title.110844Kirchenpauer, G.H. (1872) Ueber die Hydroidenfamilie Plumularidae, einzelne Gruppen derselben und ihre Fruchtbehälter. I. Aglaophenia Lx. Abhandlungen aus dem Gebiete der Naturwissenschaften herausgegeben von dem Naturwissenschaftlichen Verein in Hamburg, 5 (3), 1–52.Kramp, P.L. (1947) Hydroids collected by the “Skagerak” expedition in the eastern Atlantic 1946. Göteborgs. Kungliga Vetenskaps och Vitterhets Samhälles Handlingar, (B6), 5 (8), 1–16.Kramp, P.L. (1959). Some new and little known Indo-Pacific medusae. Videnskabelige Meddelelser fra Dansk naturhistorisk Forening i København, 121, 223–259.Lamarck, J.B. de (1816) Histoire naturelle des animaux sans vertèbres. Vol. 2. Verdière, Paris, 568 pp.Lamouroux, J.V.F. (1812) Extrait d’un mémoire sur la classification des polypes coralligènes non entièrement pierreux. Nouveau Bulletin des Sciences de la Société Philomatique de Paris, 3, 181–188.Lamouroux, J.V.F. (1821) Exposition méthodique des genres de l’ordre des polypiers, avec leur description et celle des principales espèces, figurées dans 84 planches; les 63 premières appartenant à l’histoire naturelle des zoophytes d’Ellis et Solander. Agasse, Paris, 115 pp. https://doi.org/10.5962/bhl.title.11328Le Danois, E. (1948) Les Profondeurs de la Mer. Trente ans de recherches sur la faune sous-marine au large des côtes de France. Payot, Paris, 303 pp.Leloup, E. (1937) Hydroidea, Siphonophora, Ceriantharia. I. Hydropolypes. In: Résultats scientifiques des croisières du navire-école belge “Mercator”. Mémoires du Musée royal d’histoire naturelle de Belgique, Series 2, 9, pp. 91–121.Leloup, E. (1940) Hydropolypes provenant des croisières du Prince Albert Ier de Monaco. Résultats des Campagnes scientifiques accomplies sur son yacht par le Prince Albert Ier de Monaco, 104, 1–38.Leloup, E. (1974) Hydropolypes calyptoblastiques du Chili. Report no. 48 of the Lund University Chile Expedition 1948–1949. Sarsia, 55, 1–62. https://doi.org/10.1080/00364827.1974.10411252Levinsen, G.M.R. (1893) Meduser, Ctenophorer og Hydroider fra Grønlands Vestkyst, tilligemed Bemaerkninger om Hydroidernes Systematik. Videnskabelige Meddelelser fra Dansk naturhistorisk Forening i København, 1892, 143–212 + 215–220, appendix, pls. 5–8.Linnaeus, C. (1758) Systema naturae per regna tria naturae, secundum classes, ordines, genera, species cum characteribus, differentiis, synonymis, locis. Editio decima, reformata. Laurentii Salvii, Holmiae, 823 pp. https://doi.org/10.5962/bhl.title.542Lütken, C., (1850) Nogle Bemaerkninger om Medusernes systematiske Inddeling, navnlig med Hensyn til Forbes’s History of British Naked-eyed Medusae. Videnskabelige meddelelser fra den Naturhistoriske forening i Kjöbenhavn, 1850, 15–35.Marktanner-Turneretscher, G. (1890) Die Hydroiden des k.k. naturhistorischen Hofmuseums. Annalen des Naturhistorischen Hofmuseums, 5, 195–286.Maronna, M.M., Miranda, T.P., Peña Cantero, A.L., Barbeitos, M.S. & Marques, A.C. (2016) Towards a phylogenetic classification of Leptothecata (Cnidaria, Hydrozoa). Scientific Reports, 6, 18075. https://doi.org/10.1038/srep18075Marques, A.C., Mergner, H., Höinghaus, R. & Vervoort, W. (2000) Bimeria vestita (Hydrozoa: Anthomedusae: Bougainvilliidae) senior synonym of Eudendrium vestitum (Hydrozoa: Anthomedusae: Eudendriidae). Zoologische Mededelingen, 73, 321–325.Marques, A.C., Peña Cantero, A.L., Miranda, T.P. & Migotto, A.E. (2011) Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa). Zootaxa, 3129 (1), 1–28. https://doi.org/10.11646/zootaxa.3129.1.1Martell, L., Piraino, S., Gravili, C. & Boero, F. (2016) Life cycle, morphology and medusa ontogenesis of Turritopsis dohrnii (Cnidaria: Hydrozoa). Italian Journal of Zoology, 83 (3), 390–399. https://doi.org/10.1080/11250003.2016.1203034McCrady, J., (1857) Description of Oceania (Turritopsis) nutricula nov. spec. and the embryological history of a singular medusan larva, found in the cavity of its bell. Proceedings of the Elliott Society of natutal Histtory, 1, 55–90.Medel, M.D. & Vervoort, W. (1995) Plumularian hydroids (Cnidaria: Hydrozoa) from the strait of Gibraltar and nearby areas. Zoologische Verhandelingen, Leiden, 300, 1–72.Medel, M.D. & Vervoort, W. (1998) Atlantic Thyroscyphidae and Sertulariidae (Hydrozoa, Cnidaria) collected during the CANCAP and Mauritania II expeditions of the National Museum of Natural History, Leiden, The Netherlands. Zoologische Verhandelingen, Leiden, 320, 1–83.Medel, M.D. & Vervoort, W. (2000) Atlantic Haleciidae and Campanulariidae (Hydrozoa, Cnidaria) collected during the CANCAP and Mauritania-II expeditions of the National Museum of Natural History, Leiden, The Netherlands. Zoologische Verhandelingen, Leiden, 330, 1–66.Medel, M.D., García, F.G. & Vervoort, W. (1998) The family Haleciidae (Cnidaria: Hydrozoa) from the Strait of Gibraltar and nearby areas. Zoologische Verhandelingen, Leiden, 72 (3), 29–50.Miglietta, M.P., Piraino, S., Kubota, S. & Schuchert, P. (2007) Species in the genus Turritopsis (Cnidaria, Hydrozoa): a molecular evaluation. Journal of Zoological Systematics and Evolutionary Research, 45 (1), 11–19. https://doi.org/10.1111/j.1439-0469.2006.00379.xMigotto, A.E. & Cabral, A.S. (2005) Lafoeina amirantensis (Cnidaria: Hydrozoa, Campanulinoidea), the hydroid stage of the medusa Cirrholovenia tetranema (Cnidaria: Hydrozoa, Lovenelloidea). Zootaxa, 919 (1), 1–16. https://doi.org/10.11646/zootaxa.919.1.1Millard, N.A.H. (1962) The Hydrozoa of the south and west coasts of South Africa. Part I. The Plumulariidae. Annals of the South African Museum, 46, 261–319.Millard, N.A.H. (1975) Monograph on the Hydroida of southern Africa. Annals of the South African Museum. Annale van die Suid-Afrikaanse Museum, 68, 1–513.Millard, N.A.H. (1978) The geographical distribution of southern African hydroids. Annals of the South African Museum. Annale van die Suid-Afrikaanse Museum, 74 (6), 159–200.Millard, N.A.H. & Bouillon, J. (1973) Hydroids from the Seychelles (Coelenterata). Annals Musee Royal de L´Afrique Centrale, Sciences Zoologiques, 206 (8), 1–106.Mortensen, P. al B. & Fossa, J.H. (2006) Species diversity and spatial distribution of invertebrates on deep-water Lophelia reefs in Norway. Proceedings of 10th International Coral Reef Symposium, Okinawa, Japan, 2006, pp. 1849–1860.Moura, C.J., Harris, D.J., Cunha, M.R. & Rogers, A.D. (2008) DNA barcoding reveals cryptic diversity in marine hydroids (Cnidaria, Hydrozoa) from coastal and deep-sea environments. Zoologica Scripta, 37, 93–108. https://doi.org/10.1111/j.1463-6409.2007.00312.xMoura, C.J., Cunha, M.R., Porteiro, F.M. & Rogers, A.D. (2011) The use of the DNA barcode gene 16S mRNA for the clarification of taxonomic problems within the family Sertulariidae (Cnidaria, Hydrozoa): Systematics of sertulariid hydroids. Zoologica Scripta, 40, 520–537. https://doi.org/10.1111/j.1463-6409.2011.00489.xMoura, C.J., Cunha, M.R., Porteiro, F.M., Yesson, C. & Rogers, A.D. (2012) Evolution of Nemertesia hydroids (Cnidaria: Hydrozoa, Plumulariidae) from the shallow and deep waters of the NE Atlantic and western Mediterranean. Zoologica Scripta, 41, 79–96. https://doi.org/10.1111/j.1463-6409.2011.00503.xNorman, A.M. (1875) Submarine-cable fauna. Part II. Crustacea, etc. Annals and Magazine of Natural History, Series 4, 15, 169–176, pl. 12. https://doi.org/10.1080/00222937508681053Oken, L. (1815) Okens Lehrbuch der Naturgeschichte. III. Theil. Zoologie. Vol. 1. Oken, Jena, 842 pp.Patriti, G. (1970) Catalogue des cnidaires et cténaires des côtes Atlantiques marocaines. Travaux de l’Institut Scientifique Chérifien, Série Zoologique, 35, 1–149.Pelegrí, J.L. & Peña˗Izquierdo, J. (2015) Eastern Boundary currents off North˗West Africa. In: Valdés, L. & Déniz-González, I. (Eds.), Oceanographic and biological features in the Canary Current Large Marine Ecosystem. IOC Technical Series. No. 115. IOC-UNESCO, Paris. pp. 81–92.Pelegrí, J.L., Peña-Izquierdo, J., Machín, F.J., Meiners, C. & Presas-Navarro, C. (2017) Oceanography of the Cape Verde Basin and Mauritanian Slope Waters. In: Ramos, A., Ramil, F. & Sanz, J.L. (Eds.), Deep sea ecosystems off Mauritania: Researching marine biodiversity and habitats in West African Deep-waters. Springer, Dordrecht, pp. 119–153. https://doi.org/10.1007/978-94-024-1023-5_3Peña Cantero, A.L. (2004) How rich is the deep-sea Antarctic benthic hydroid fauna? Polar Biology, 27, 767–774. https://doi.org/10.1007/s00300-004-0654-9Peña Cantero, A.L. & García Carrascosa, A.M. (2002) The benthic hydroid fauna of the Chafarinas Islands (Alborán Sea, western Mediterranean). Zoologische Verhandelingen, Leiden, 337, 1–180.Peña Cantero, A.L. & Horton, T. (2017) Benthic hydroids (Cnidaria, Hydrozoa) from bathyal and abyssal depths of the Northeast Atlantic held in the modern Discovery Collections. Zootaxa, 4347 (1), 1–30. https://doi.org/10.11646/zootaxa.4347.1.1Peña Cantero, A.L., García Carrascosa, A.M. & Vervoort, W. (1998) On the species of Filellum Hincks, 1868 (Cnidaria: Hydrozoa) with the description of a new species. Journal of Natural History, 32, 297–315. https://doi.org/10.1080/00222939800770151Picard, J. (1951) Hydraires littoraux du Sénégal récoltés par H. Sourie aux environs de Dakar. Bulletin de l’Institut français d’Afrique noir, 13 (1), 109–115.Pictet, C. & Bedot, M. (1900) Hydraires provenant des campagnes de l’ «Hirondelle» (1886–1888). Résultats des campagnes scientifiques du prince de Monaco, 18, 1–59, pls. 1–10. https://doi.org/10.5962/bhl.title.11294Quelch, J.J. (1885) On some deep-sea and shallow water Hydrozoa. Annals and Magazine of Natural History, Series 5, 16 (91), 1–20. https://doi.org/10.1080/00222938509487499Ramil, F. (1988) Hidrozoos de Galicia. Tesis doctoral, Universidad de Santiago de Compostela, Santiago de Compostela, Galicia, 525 pp.Ramil, F. & Iglesias, A. (1988) Sobre la presencia de Opercularella panicula (Sars, 1873) (Cnidaria, Hydrozoa) en las costas de la Península Ibérica. Thalassas, 6, 79–82.Ramil, F. & Vervoort, W. (1992) Report on the Hydroida collected by the “BALGIM” expedition in and around the Strait of Gibraltar. Zoologische Verhandelingen, Leiden, 277, 1–262.Ramil, F. & Vervoort, W. (2008) Note on Streptocaulus multiseptatus (Bale, 1915) (Cnidaria: Leptolida: Aglaopheniidae), with the description of its gonosome. Zoologische Medelingen Leiden, 82, 417–422.Ramil, F., Parapar, J. & Vervoort, W. (1992) The genus Sertularella Gray, 1848 (Cnidaria: Hydrozoa) along the coasts of Galicia (Spain). Zoologische Verhandelingen, Leiden, 66, 493–524.Ramil, F., Vervoort, W. & Ansin, J.A. (1998) Report on the Haleciidae and Plumularioidea (Cnidaria, Hydrozoa) collected by the French SEAMOUNT 1 expedition. Zoologische Verhandelingen, Leiden, 322, 1–42.Ramos, A., Ramil, F. & Sanz, J.L. (2017) Deep˗Sea Ecosystems off Mauritania: An Introduction. In: Ramos, A., Ramil, F. & Sanz, J.L. (Eds.), Deep sea ecosystems off Mauritania: Researching marine biodiversity and habitats in West African Deep-waters. Springer, Dordrecht, pp. 1–51. https://doi.org/10.1007/978-94-024-1023-5_1Ramos, A., Sanz, J.L., Ramil, F., Agudo, L.M. & Presas-Navarro, C. (2017) The Giant Cold˗Water Coral Mounds Barrier off Mauritania. In: Ramos, A., Ramil, F. & Sanz, J.L. (Eds.), Deep sea ecosystems off Mauritania: Researching marine biodiversity and habitats in West African Deep-waters. Springer, Dordrecht, pp. 481–525. https://doi.org/10.1007/978-94-024-1023-5_13Redier, L. (1965) Hydraires et Bryozoaires du Golfe de Guinêe. Bulletin du Muséum National D’Histoire Naturelle, 37, 367–394.Rees, W.J., Thursfield, S. (1965) The hydroid collections of James Ritchie. Proceedings of the Royal Society of Edinburgh, (B), 69 (1–2), (2), 34–220. https://doi.org/10.1017/S0080455X00010122Rees, W.J. & Vervoort, W. (1987) Hydroids from the John Murray Expedition to the Indian Ocean, with revisory notes on Hydrodendron, Abietinella, Cryptolaria and Zygophylax (Cnidaria, Hydrozoa). Zoologische Verhandelingen, 237, 1–209.Rees, W.J. & White, E. (1966) New records and fauna list of hydroids from the Azores. Annals and Magazine of Natural History, Series 13, 9, 271–284. https://doi.org/10.1080/00222936608656051Ritchie, J. (1907) On collections of the Cape Verde Islands marine fauna, made by Cyril Crossland, M.A. (Cantab.), B.Sc. (Lond.), F.Z.S., of St. Andrews University, July to September, 1904. The Hydroids. Proceedings of the Zoological Society of London, 77, 488–514. https://doi.org/10.1111/j.1469-7998.1907.tb06944.xRoberts, J.M. & Cairns, S.D. (2014) Cold-water corals in a changing ocean. Current Opinion in Environmental Sustainability, 7, 118–126. https://doi.org/10.1016/j.cosust.2014.01.004Roberts, J.M., Wheeler, A.J. & Freiwald, A. (2006) Reefs of the Deep: The Biology and Geology of Cold-Water Coral Ecosystems. Science, 312, 543–547. https://doi.org/10.1126/science.1119861Ronowicz, M. (2007) Benthic hydroids (Cnidaria: Hydrozoa) from Svalbard waters—biodiversity and distribution. Journal of the Marine Biological Association of the United Kingdom, 87, 1089–1094. https://doi.org/10.1017/S0025315407055142Ronowicz, M., Włodarska-Kowalczuk, M. & Kuklinski, P. (2013) Depth- and substrate-related patterns of species richness and distribution of hydroids (Cnidaria, Hydrozoa) in Arctic coastal waters (Svalbard). Marine Ecology, 34 (Supplement 1), 165–176. https://doi.org/10.1111/maec.12034Russell, F.S. (1940) On the nematocysts of hydromedusae III. Journal of the Marine Biological Association of the United Kingdom, 24, 515–523. https://doi.org/10.1017/S0025315400045422Russell, F.S. (1953) The medusa of the British Isles. Anthomedusae, Leptomedusae, Limnomedusae, Trachymedusae and Narcomedusae. Cambridge University Press, Cambridge, 538 pp.Saemundsson, B. (1911) Bidrag til Kundskaben om de islandske Hydroider. II. Videnskabelige Meddelelser fra Den Danske Naturhistoriske Forening, 63, 67–107.Sars, M. (1863) Bemaerkninger over fire norske Hydroider. Forhandlinger i Videnskabsselscabet i Kristiania, 1862, 25–39.Sars, G.O. (1874) Bidrag til Kundskaben om Norges Hydroider. Forhandlinger i Videnskabs-Selskabet i Kristiana, 1873, 91–150.Schuchert, P. (1996) The marine fauna of New Zealand: athecate hydroids and their medusae (Cnidaria: Hydrozoa). Elsevier Science, Wellington, 159 pp.Schuchert, P. (1997) Review of the family Halopterididae (Hydrozoa, Cnidaria). Zoologische Verhandelingen, Leiden, 309, 1–161.Schuchert, P. (2000) Hydrozoa (Cnidaria) of Iceland collected by the BIOICE programme. Sarsia, 85, 411–438. https://doi.org/10.1080/00364827.2000.10414592Schuchert, P. (2001) Hydroids of Greenland and Iceland (Cnidaria, Hydrozoa). Bioscience, 53, 1–185.Schuchert, P. (2004) Revision of the European athecate hydroids and their medusae (Hydrozoa, Cnidaria): families Oceanidae and Pachycordylidae. Revue suisse de Zoologie, 111, 315–369. https://doi.org/10.5962/bhl.part.80242Schuchert, P. (2005) Taxonomic revision and systematic notes on some Halecium species (Cnidaria, Hydrozoa). Journal of Natural History, 39, 607–639. https://doi.org/10.1080/00222930400001319Schuchert, P. (2007) The European athecate hydroids and their medusa (Hydrozoa, Cnidaria): Filifera Part 2. Revue suisse de Zoologie, 114, 195–396. https://doi.org/10.5962/bhl.part.80395Schuchert, P. (2012) North-West European Athecate Hydroids and their Medusae. Synopses of the British Fauna, New Series, 59, 1–364.Schuchert, P. (2014) High genetic diversity in the hydroid Plumularia setacea: A multitude of cryptic species or extensive population subdivision? Molecular Phylogenetics and Evolution, 76, 1–9. https://doi.org/10.1016/j.ympev.2014.02.020Schuchert, P. (2018) World Hydrozoa Database. Earleria panicula (G.O. Sars, 1874). Available from: http://www.marinespecies.org/hydrozoa/aphia.php?p=taxdetails&id=1255613 (accessed 3 September 2020)Schuchert, P., Hosia, A. & Leclère, L. (2017) Identification of the polyp stage of three leptomedusa species using DNA barcoding. Revue suisse de Zoologie, 124 (1), 167–182.Stechow, E. (1907) Neue japanische Athecata und Plumularidae aus der Sammlung Dr. Doflein. Zoologischer Anzeiger, 32 (7), 192–200.Stechow, E. (1909) Hydroidpolypen der japanischen Ostküste. 1. Theil. Athecata und Plumularidae. In: Doflein, F. (Ed.), Beiträge zur Naturgeschichte Ostasiens. Abhandlungen der Königlich Bayerischen Akademie der Wissenschaften, 1 (6), 1–111.Stechow, E. (1913a) Neue Genera thecater Hydroiden aus der Familie der Lafoeiden und neue Species von Thecaten aus Japan. Zoologischer Anzeiger, 43 (3), 137–144.Stechow, E. (1913b). Hydroidpolypen der japanischen Ostküste. II. Teil: Campanularidae, Halecidae, Lafoeidae, Campanulinidae und Sertularidae, nebst Ergänzungen zu den Athecata und Plumularidae. In: Doflein, F., Beiträge zur Naturgeschichte Ostasiens.—Abh. math.phys. Historische Klasse der Königlichen bayerischen Akademie der Wissenschaften, 3 (2), pp. 1–162. https://doi.org/10.5962/bhl.title.11621Stechow, E. (1921) Neue Genera und Species von Hydrozoen und anderen Evertebraten. Archiv für Naturgeschichte, Abteilung A, 3, Heft, 87, 248–265.Stramma, L. & Schott, F. (1999) The mean flow field of the tropical Atlantic Ocean. Deep-Sea Research Part II: Topical Studies in Oceanography, 46 (1), 279–303. https://doi.org/10.1016/S0967-0645(98)00109-XSvoboda, Α. (1979) Beitrag zur Ökologie, Biometrie und Systematik der Mediterranen Aglaophenia Arten (Hydroidea). Zoologische Verhandelingen, Leiden, 167, 1–114.Svoboda, A. & Cornelius, P.F.S. (1991) The European and Mediterranean species of Aglaophenia (Cnidaria : Hydrozoa). Zoologische Verhandelingen, Leiden, 274, 1–70.Teissier, G. (1965) Inventaire de la faune marine de Roscoff. Cnidaires-Cténaires. Travaux de la Station Biologique de Roscoff, 16, 1–53.Van Soest, R.W.M. (1993) Distribution of sponges on the Mauritanian continental shelf. Hydrobiologia, 258, 95–106. https://doi.org/10.1007/BF00006189Van Soest, R.W.M. and de Voogd, N.J. (2015) Sponge species composition of north-east Atlantic cold-water coral reefs compared in a bathyal to inshore gradient. Journal of the Marine Biological Association of the United Kingdom, 95 (7), 1461–1474. https://doi.org/10.1017/S0025315413001410Vanhöffen, E. (1910) Die Hydroiden der Deutschen Südpolar-Expedition 1901–1903. Deutsche Südpolar-Expedition 1901–1903, 11, Zoologie 3, 269–340.Vervoort, W. (1946) Exotic hydroids in the collections of the Rijksmuseum van Natuurlijke Historie and the Zoological Museum at Amsterdam. Zoologische Mededelingen, Leiden, 26 (1–4), 287–351.Vervoort, W. (1946) Exotic hydroids in the collections of the Rijksmuseum van Natuurlijke Historie and the Zoological Museum at Amsterdam. Zoologische Mededelingen, Leiden, 26 (1–4), 287–351.Vervoort, W. (1972) Hydroids from the Theta, Vema and Yelcho cruises of the Lamont-Doherty geological observatory. Rijksmuseum van Natuurlijke Historie, Leiden, Netherlands, 120, 1–247.Vervoort, W. (2006) Leptolida (Cnidaria: Hydrozoa) collected during the CANCAP and Mauritania-II expeditions of the National Hystory, Leiden, the Netherlands [Anthoathecata, various families of Leptothecata and addenda]. Zoologische Mededelingen, Leiden, 80, 181–318.Vervoort, W. & Faasse, M. (2009) Overzicht van de Nederlandse Leptolida (= Hydroida) (Cnidaria: Hydrozoa). Nederlandse Faunistische Mededelingen, 32, 1–207.Vervoort, W. & Watson, J.E. (2003) The marine fauna of New Zealand. Leptothecata (Cnidaria: Hydrozoa) (Thecate Hydroids). NIWA Biodiversity Memoir, 119, 1–540.Westphal, H., Beuck, L., Braun, S., Freiwald, A., Hanebuth, T., Hetzinger, S., Klicpera, A., Kudrass, H., Lantzsch, H., Lundälv, T., Mateu Vicens, G., Preto, N., Reumont, J.V., Schilling, S., Taviani, M. & Wienberg, C. (2012) Report of Cruise Maria S. Merian 16/3—Phaeton—Paleoceanographic and paleo˗climatic record on the Mauritanian shelf. Institut für Meereskunde der Universität Hamburg, 136 pp.Wienberg, C., Titschack, J., Freiwald, A., Frank, N., TomasLundälv, T., Taviani, M., Beuck, L., Schröder-Ritzrau, A., Krengel, T. and Hebbeln, D. (2018) The giant Mauritanian cold-water coral mound province: Oxygen control on coral mound formation. Quaternary Science Reviews, 185, 135–152. https://doi.org/10.1016/j.quascirev.2018.02.012Wright, T.S. (1859) Observations on British zoophytes. Edinburgh new Philosophical Journal, 10, 105–114.

Brittle stars constitute a common and highly diverse component of epibenthic communities, and they can form dense aggregations on the seabed of all oceans worldwide. Nevertheless, there is limited information on the diversity and distribution of these echinoderms in Northwest Africa. Between 2004 and 2012, 10 multidisciplinary Spanish and Norwegian surveys were conducted off Northwest Africa—between the Strait of Gibraltar and Sierra Leone border—from a depth of 19 to 1888 m. During these surveys, we sampled 1298 stations, and about one million individuals and 124 kg of brittle stars were collected from 502 stations. Forty-two species belonging to eight ophiuroid families considered as suspension feeders were collected from 296 stations and represented 93.4% of the total abundance and 75% of the total ophiuroid-specific richness. Ophiacanthidae was the richest and most abundant family, with 15 species and estimated densities up to almost 4 × 10⁵ by 0.1 square kilometre. The other families found abundantly were Amphiuridae, Ophiotrichidae and Ophiactidae, represented by six, five and four species each, respectively. Ophiotrichidae, Ophiacanthidae and Gorgonocephalidae presented the largest biomass among the suspension-feeder families (35.5%, 33.8% and 28.2%, respectively), and Ophiotrichidae is a well-represented family along the Northwest African coast. The most remarkable concentrations and highest diversity values were detected on the upper slope (depth, 400–600 m) off Western Sahara. Between 24°N and 22°N, we collected huge concentrations of Ophiacantha abyssicola and up to six species per station. This area has permanent and intense upwelling conditions and is out of the minimum oxygen zone. We also noted significant densities and richness at Cape Ghir and Cape Blanc, where important filaments of nutrient-rich waters occur, and at Guinea-Bissau, which is affected by nutrient river inputs. The multivariate analysis clearly separated the brittle stars into two main assemblages, across latitudinal and bathymetrical gradients: northern latitude (Morocco and Northern Sahara) from the area south of 24°N and from the continental shelf–upper slope to the deep slope., Sí

Four multidisciplinary oceanographic surveys were conducted in November and December from 2007 to 2010, along the Mauritanian coast (NW Africa). A total of 10,514 brachyuran crabs belonging to 33 species were captured in 316 hauls at depths between 79 and 1867 m. The most specious family was Inachidae represented by nine species; the remaining 24 species belonged to 16 other brachyuran families. Monodaeus cristulatus is reported for the first time since its original description. Seven other species, Ethusa rugulosa, Pseudomyra mbizi, Inachus grallator, Macropodia gilsoni, Macropodia hesperiae, Solenolambrus noordendei and Spinolambrus notialis extend their range of distribution northwards and, together with Goneplax barnardi, are reported here for the first time in Mauritanian waters. New data about depth ranges are reported for Acanthocarpus brevispinis, Ethusa rugulosa, Inachus aguiarii, Inachus grallator, Inachus nanus, Macropodia macrocheles, Solenolambrus noordendei, Spinolambrus notialis, Liocarcinus corrugatus and Monodaeus cristulatus. New data relating to the spawning period for most of the species are also included, as are some biogeographic and bathymetric considerations about brachyurans studied in the area., Sí

This paper deals with species of the deep-water marine lobsters and lithodids collected on soft and rocky bottoms during the four Spanish Maurit surveys from 2007 to 2010 in Mauritanian waters, at depths between 80 and 2000 m. The collection is represented by eight species included in the infraorders Astacidea, Achelata, and Polychelida, and by five species of the family Lithodidae. The true lobster Nephropsis atlantica, the blind lobster Stereomastis nana, and the king crab Paralomis cristulata are reported for the first time in Mauritanian waters, while the presence of the slipper lobster Scyllarus subarctus is confirmed in the area. New data on the bathymetric distribution of P. cristulata and Lithodes ferox are also included, Sí

Ophiuroidea constitutes the largest class of the phylum Echinodermata. It includes families with suspension-feeder behaviour that can be found in dense aggregations in all oceans worldwide. Ophiothrix maculata was known as a rare suspension-feeder brittle star, with only four records in the Eastern Central Atlantic dating from almost 100 years ago. During the ten multidisciplinary Spanish and Norwegian surveys carried out from 2004 to 2012 off Northwest Africa, between the Gibraltar Strait and the Sierra Leone border from 19 to 1888 m depth, we sampled 1298 stations. We gathered about one million individuals and 124 kg of brittle stars at 501 of the stations. Eight hundred and thirty-two specimens of Ophiothrix maculata were collected at six localities on the continental slope off Mauritania, Western Sahara and Guinea Bissau, at depths between 155 and 594 m. The Guinea Bissau samples represent the southernmost current record for the species. Even though Ophiothrix maculata has been previously recorded only in isolation, we discovered dense concentrations on the Mauritanian slope on the Wolof's Seamount (580 individuals) and off the Western Sahara, in a Lophelia pertusa reef (202 individuals). In this paper, we describe these findings and discuss the association of this species to hard-bottom habitats and high primary production areas, outside of the oxygen minimum zone (OMZ). We also analyse what other factors may explain the patchy distribution of O. maculata on the Northwest African slope, Sí

Echinoderms are the most important taxa of megabenthic invertebrates on the Mauritanian deep-sea floor, both in density and biomass . The phylum is represented by approximately 82 species, Ophiuroidea and Asteroidea being the most diverse classes (25 and 23 species, respectively), followed by Holothuroidea and Echinoidea (19 and 12 species, respectively). Crinoidea is poorly represented by only three species. Holothuroidea (sea cucumbers) are, undoubtedly, the main component of deep Mauritanian echinoderms, accounting for 85.5% of numerical abundance and 96.0% of biomass. Species belonging to Echinothurioida are dominant among the sea urchins . The most common echinoderm species are Phormosoma placenta , Enypniastes eximia , Psilaster cassiope , Benthothuria funebris, Ophiernus alepidotus , Pseudarchaster gracilis gracilis and Ophiura flagellata . The Mauritanian echinoderm fauna are mostly composed of species with Atlantic distribution (80.5%) and a smaller group of wide distribution species (19.5%). Only three species, two sea stars and one ophiuroid, could be considered as endemic to Macaronesian African waters : Hymenaster roseus , Dyptaster mollis and Ophiothrix maculata . The bathymetric distribution of species and multivariate analysis clearly identify two main assemblages : the first groups the stations located on the deep shelf and upper slope (

During the four Maurit surveys carried out annually from 2007 to 2010, 342 trawl stations were sampled off the Mauritanian coast between 80 and 2000-m depth. Hydroids were captured at 174 stations, totalling 6169 colonies belonging to 63 species and 19 families . Most of the species were Leptothecata and only seven belonged to Anthoathecata . Thirty-two of the 63 species are new records for Mauritania. Plumulariidae showed the highest species richness (8 species), followed by Sertulariidae and Campanulariidae (7 species), Lafoeidae , Haleciidae and Aglopheniidae (6 species). The most abundant were Sertulariidae , followed by Aglaopheniidae, Plumulariidae, Campanulariidae, Halopterididae and Haleciidae . The ability of hydroids to colonize Mauritanian soft bottom s was driven by hydrorhizal modifications for anchoring the colony to the sediment and by epizoism on 11 invertebrate groups. Families whose species developed both strategies and those which were typically epibionts on hydroids were the most frequent and abundant. Most of the species were eurybathic (58 species), with four species recorded only in the coastal realm, 18 exclusively in the deep benthic realm and 41 in both realms. Therefore, overall hydroid diversity was highest in the deep benthic realm . Biogeographical components included two main groups: species with a wide distribution (59%) and species of Atlantic distribution (41%); our results also emphasize the similarity between the Mauritanian hydroid fauna and the Atlantic-Mediterranean region. Only one species, Hydractinia multitentaculata (Millard 1975), has West African distribution. No endemic species were reported.

This chapter describes the main features of the giant mounds structure running parallel to the shelf break along the Mauritanian slope between the Senegalese border and Cape Timiris. At over 580 km long, it is the world’s largest identified cold-water coral mounds barrier and, in our opinion, conforms to a single province, the Mauritanian Province . The Maurit series of Spanish-Mauritanian oceanographic surveys collected multibeam echosounder data, performed 16 conductivity-temperature-depth (CTD) profiles and 13 rock dredge samplings , which led to the mapping of the reef complex , oceanographic characterization of water masses and faunistic studies. The reef framework is mostly composed of dead coral, mainly Lophelia pertusa , with a minor fraction of Madrepora oculata . Associated fauna mainly consists of Acesta excavata and other bivalve and prosobranch molluscs, soaked in abundant, fine compacted mud . At least 150 macrobenthic species of 27 high-range taxa inhabit this reef. The coral surface is either almost devoid of sessile fauna or poorly colonized by small encrusting epifaunal species. We only found fragments of living L. pertusa in the four southernmost stations. The multivariate analysis clearly groups some areas where corals and other suspension-feeders exhibit the highest diversity. Despite their small size, the 17 taxa of suspension-feeders represent 75% of abundance and biomass . Surprisingly, despite the unfavourable history of climatic change episodes, current environmental conditions, deterioration and overall faunistic poverty of the mounds, Lophelia specimens still survive in some areas , sheltering communities of apparently similar structure to those on well-developed cold-water coral reefs in Northern Atlantic latitudes.

A total of 16,036 cephalopods belonging to 48 species were caught on the Mauritanian continental shelf and slope, between 80 and 2000 m depth, in November–December of 2007–2010 during the joint Spanish-Mauritanian surveys . Samples were collected using a commercial bottom trawl . Ommastrephidae was the most abundant family (71.1%) in number and weight. Neritic and benthic species of Loliginidae , Octopodidae and Sepiidae represented 7.3, 6.2 and 5.3% of the total number, respectively. A checklist of 132 Mauritanian species is shown. The geographical and bathymetric distribution of species sampled in the area is discussed. Eight species, Mastigoteuthis flammea , Cycloteuthis akimushkin i, Muusoctopus fuscus , M. janarii, Bathypolypus arctic us, B. biardii, B. valdiviae and Graneledone verrucosa are recorded for the first time in Mauritanian waters. This is the first time that M. fuscus is cited in Atlantic waters and that B. valdiviae is observed in the northern hemisphere. Two main cephalopods assemblages , Shelf and Slope, were identified in the zone. Both are largely dominated by ommastrephid species which could constitute an important resource not currently exploited in the area. This work provides the first data on benthic octopods species that inhabit the deep waters of Northwest Africa.

One of the objectives of the Maurit˗1011 survey was the environmental and faunistic characterization of a small seamount of 200 m in height, discovered during the Maurit˗0911 expedition, on the upper continental slope south of Nouakchott, at 17°08′ 50″N and 16°46′ 38.1″W. It is an isolated conical structure with small ridges, almost parallel to the edge of the continental shelf and not connected to nearby coral mounds barrier. The geomorphology of this submarine elevation, as well as the debris from a hydrothermal vents or cold seeps discovered in the rock dredge samples suggests a diapiric association because no hydrothermal benthic fauna was found. The summit of the seamount was covered with sponges belonging mainly to the family Geodiidae, and ophiuroids belonging to the suspension-feeders family Ophiotrichidae. We also found accompanying fauna comprising about 50 species, mainly consisting of molluscs and decapods. Despite its small size but taking into account the richness of the suspension-feeders community living on it, this Wolof’s Seamount (so called to honour the artisanal fishermen who first discovered it) could be promoted as a marine protected area in the Mauritanian continental margin.

Quantitative data were collected with a 3.5 m beam-trawl gear at 25 stations along five latitudinal transects , covering five bathymetric strata from 100 to 2000 m depth. More than 500 species belonging to 35 epibenthic high-range taxa are present in Mauritanian deep-sea bottom s. Pisces , Decapoda and Polychaeta , represented by 111, 80 and 56 species, respectively, constituted the richest groups, being the first two collected at all stations. Decapoda were dominant in abundance (55.8% of the total), although in biomass they shared their dominance with Actinopterygii and Holothuroidea (29.4, and 26.0%, respectively). Although suspension feeders were represented by 131 species (25.7%), they only accounted for 9% of the abundance and 1% of biomass (small-sized species). Low diversity indices varied widely between localities but showed no latitudinal pattern . Richness and densities decreased with increasing depth, a strongly marked trend in the case of densities, which peaked on the deep shelf and upper slope (150–300 m), while the biomass remain standing showing only minimum values at 500 m depth. Depth seems to be the strongest factor determining the structure and composition of the four main epibenthic assemblages identified on the deep shelf (150 m), upper slope (300–550 m), middle slope (1000 m) and deep slope (1600 m). The two shallowest assemblages were clearly separated from the deeper ones and were typified by different decapods and fish species , while the two deepest assemblages were characterized by echinoderms and fishes.

This publication is the third in a series of accounts on large collections of Plumularioidea McCrady, 1859 (Cnidaria, Hydrozoa, Hydroidolina) obtained during several French expeditions to the Philippines region, Vanuatu, New Caledonia, Fiji, and the Marquesas Islands. Additional material from Mozambique was also examined and is discussed. A total of 17 species, belonging to the families Kirchenpaueriidae Stechow, 1921 (two species) and Plumulariidae McCrady, 1859 (15 species), are scrutinized and illustrated in the present report. Three new species of the genus Plumularia Lamarck, 1816 are described (Plumularia bathyale n. sp., Plumularia contraria n. sp., Plumularia pseudocontraria n. sp.). The name Plumularia milsteinae n. nom., is proposed for Plumularia spiralis Milstein 1976, a permanently invalid junior homonym of Plumularia spiralis Billard, 1911. Polyplumaria kossowskae (Billard, 1911) is recorded for the first time since its original description. Two species of Plumularia are identified ...

One new genus ( Schizoplumularia ) and three new species ( Schizoplumularia vervoorti , S. geniculata and S. elegans ) of plumulariids are recognized and described from large collections of plumularioid hydroids collected in New Caledonia and vicinity during several French expeditions. During taxonomic studies of these hydroids, colonies were compared with type material of Plumularia insignis Allman, 1883 and several other similar species-group taxa. As a result, three of the latter ( P. flabellum Allman, 1883, P. conjuncta Billard, 1913, and P. billardi nom. nov.) are recognized as valid in addition to P. insignis . The binomen P. billardi is a replacement name for P. insignis var. gracilis Billard, 1913. In being elevated to the rank of species in this work, it becomes an invalid junior primary homonym of several others having the same name.

Neopilumnoplax corallicola n. sp. is described from waters off Mauritania on the basis of two specimens collected during the Spanish-Mauritanian survey BMaurit- 0911^ from 488 m over a giant cold-water coral reef running from Cape Timiris to the Senegalese border. The new species is readily separated from its congeners by the shape of the front and anterolateral teeth, the low granulation on the dorsal carapace, and the morphology of the cheliped and ambulatory legs. This is the first record of the family from the Northeastern Atlantic and the second record of the genus in West Africa. A diagnosis of the family Mathildellidae with a key to genus level, as well as dichotomous and tabular keys to the world species of the genus Neopilumnoplax, are included., MAVA (Contract 12087 Coastal West Africa C4/2012), SI

Agís, José Ansín, Vervoort, Willem, Ramil, Fran (2009): Hydroids of the family Halopterididae (Cnidaria, Hydrozoa) collected in the western Pacific by various French expeditions. Zoosystema 31 (1): 33-61, DOI: 10.5252/z2009n1a3, URL: http://www.bioone.org/doi/abs/10.5252/z2009n1a3

The Ponto-Caspian hydroid Cordylophora caspia has been found for the first time in the Tagus estuary. There is only one previous citation for this invasive species in Portuguese waters. The colonies of C. caspia were branched and had healthy gastrozooids and gonophores. The specimens were collected from a saline boundary zone characterized by high fluctuations in salinity (maximum of 15.3 and minimum of 0.2) and high suspended solids loading. Cordylophora caspia is capable of colonizing man-made infrastructures such as industrial facilities and can inhabit both brackish and freshwater environments. These features of C. caspia, together with its resilience when in a dormant stage (menonts), indicate that the monitoring of this invasive species is advisable in the Tagus estuary.

The first record of the non-indigenous Corella eumyota on the Galicia coast (north-west Spain) is reported. One hundred and forty-one specimens of this solitary ascidian were found on soft bottoms at 12 m depth in the inner part of the Ria de Vigo. This is a species from cooler waters of the southern hemisphere and was recorded for the first time in the northern hemisphere in 2002, in France. The specimens have been compared with Antarctic and South American museum samples. Some intraspecific variability was noted.

The Maurit surveys along the Mauritanian coast revealed the small collection of thalassinideans examined in this work. A total of four species were identified, of which Ezaxius ferachevali n. gen., n. sp. is described and figured here. Calocaris macandreae Bell, 1853 is the most abundant species, while the presence of Calocarides coronatus (Trybom, 1904) is confirmed on the West African coast. Trypaea oblonga n. comb. is proposed for Callianassa oblonga Le Loeuff & Intes, 1974 and it has been recaptured for the first time since its original description, with the addition of a female specimen. We also include remarks on the current status of thalassinidean systematics.

Thirteen hermit crab species of the families Diogenidae, Paguridae and Parapaguridae were captured in deep waters off Mauritania during Maurit surveys. A new species of the genus Paguristes, Paguristes candelae n. sp., is described. Areopaguristes mauritanicus n. comb. is proposed for Paguristes mauritanicus Bouvier, 1906 and Pseudopaguristes marocanus n. comb. for Paguristes marocanus A. Milne-Edwards & Bouvier, 1892; the females of the latter species are reported for the first time. Our data extends the geographical distribution of Pseudopaguristes marocanus southwards and that of Paragiopagurus macroceros northwards. Both species, together with Diogenes pugilator (Roux, 1829), are recorded for the first time in Mauritanian waters. New data about bathymetric ranges are also reported for Pseudopaguristes marocanus n. comb., Areopaguristes mauritanicus n. comb. and Paragiopagurus macroceros.

This paper is the result of the study of a squat lobsters collection obtained along the Mauritanian coast, between 91 and 1867 m depth, during the 'MAURIT' surveys carried out in the period from 2007 to 2010. Eumunida bella de Saint Laurent & Macpherson, 1990 (Chirostyloidea) and six species of Munida and Munidopsis (Galatheoidea) are reported in the present work.A new species, Munidopsis anaramosae n. sp. collected off northwestern Banc d'Arguin at 1000-1012 m depth, is described and illustrated. The presence of an eyespine that arises distally from the middle end of the cornea, walking legs merus spinose on dorsal and ventral margins and cheliped merus ventrally unarmed distinguish it from related species. Munida chunii Balss, 1913 is redescribed here and the new records of Munida guineae Miyake & Baba, 1970, M. speciosa von Martens, 1878 and Munidopsis chunii Balss, 1913 extend their geographical distribution northwards, and in the case of the last species, increase its bathymetric range.