Open Access Open Access  Restricted Access Subscription or Fee Access


New genus and two new species of the family Ethmolaimidae (Nematoda: Chromadorida), found in two different cold-seep environments



This study describes a new genus Dystomanema gen. nov. with two new species, D. cadizensis sp. nov. and D. brandtae sp. nov. within the family Ethmolaimidae, subfamily Neotonchinae, based on specimens from two low-activity cold-seep environments at distant geographical locations. The new genus was first identified in samples from the Darwin mud volcano (1100m depth) in the Gulf of Cádiz and later on also found in samples from a low-activity seep in the Larsen B embayment (820m depth) off the eastern Antarctic Peninsula. Until now, the family Ethmolaimidae contained nine genera: Ethmolaimus and Paraethmolaimus in the subfamily Ethmolaiminae, and Comesa, Filitonchoides, Filitonchus, Gomphionchus, Gomphionema, Nannolaimus, and Neothonchus in the subfamily Neotonchinae. The most important family characteristics are: an annulated cuticle bearing transverse rows of dots, cephalic sensilla arrangement of 6+6+4, a spiral amphid, an oesophagus with muscular posterior bulb, paired gonads and males with cup-shaped precloacal supplements. The new genus resembles Comesa and Neotonchus, but is typified by a ventrally displaced oral opening with three very small teeth that are easily overlooked. D. cadizensis gen. nov. sp. nov. is characterized by the 1401-2123µm long body; cuticle transversally striated with fine punctation; head conical; low lips; amphid spiralled 3 turns, oral opening ventrally displaced, male with outstretched testes; spicules of equal size; gubernaculum plate-like and ten to twelve conspicuous cup-shaped precloacal supplements with external longitudinal articulated flange. D. brandtae gen. nov. sp. nov. can be distinguished by the 2438-3280µm long body; cuticle transversally striated with fine punctuation; head conical; low lips; amphid spiraled 3+ turns; oral opening ventrally displaced; male with anterior testes outstretched and posterior one smaller and reflexed; spicules of equal size; gubernaculum plate-like and twenty conspicuous cup-shaped precloacal supplements with external longitudinal articulated flange. Notes on the ecology and habitat of the new genus are provided in light of its discovery in cold-seep environments.



Antarctic, Larsen, Southern Ocean, Gulf of Cádiz, Northeast Atlantic, Dystomanema gen. nov., Dystomanema cadizensis gen. nov. sp. nov., Dystomanema brandtae gen. nov. sp. nov., cold seep

Full Text:

PDF/A (13,830 KB)


Andrassy, I. (1992) A census of genera and subgenera of free-living nematodes described ensuing Andrássy’s book, 1976. Opuscula Zoologica Budapest, 25, 137–148.

Austen, M.C., Warwick, R.M. & Ryan, K.P. (1993) Astomonema Southwardorum sp. nov. A Gutless nematode dominant in a methane seep area in the North-Sea. Journal of the Marine Biological Association of the United Kingdom, 73, 627–634.

Chitwood, B.G. (1933) A revised classification of the Nematoda. The Journal of Parasitology, 20, 131.

Cobb, N.A. (1913) New Nematode genera found inhabiting fresh water an non-brackish soils. Journal of the Washington Academy of Sciences, 3, 432–444.

Cobb, N.A. (1920) One hundred new nemas. (Type species of 100 new genera). In: Contributions to a Science of Nematology. Walverly Press, Baltimore, pp. 217–343.

Cobb, N.A. (1933) New nemic genera and species, with taxonomic notes. Edited by Margaret V. Cobb. The Journal of Parasitology, 20, 81–94.

Dando, P.R., Austen, M.C., Burke, R.A., Kendall, M.A., Kennicutt, M.C., Judd, A.G., Moore, D.C., O’Hara, S.C.M., Schmalijohann, R. & Southward, A.J. (1991) Ecology of a North-Sea Pockmark with an active methane seep. Marine Ecology Progress Series, 70, 49–63.

Deprez T, Steyaert M, Vanaverbeke J, Speybroeck J, Raes M, et al. (2005) NeMys. World Wide Web electronic publication. Available from: (Accessed 1 May 2011)

De Coninck, L.A.P. (1965). Systématique des nématodes. Traité de zoologie: anatomie, systématique biologie, 4, 2.

Decraemer, W. & Smol, N. (2006) Order Enoplida. In: Abebe, E., Traunspurger, W. & Andrássy (eds). Freshwater Nematodes : Ecology and Taxonomy. CABI Publishing, pp. 497–573.

De Ley, P. & Blaxter, M.L. (2002) Systematic position and phylogeny. The biology of nematodes, 1–30.

Domack E, Ishman S, Leventer A, Sylva S, Willmott V. & Huber, B. (2005) A chemotrophic ecosystem found beneath Antarctic ice shelf. EOS, 86, 269, 271–272.

Filipjev, I. (1917) Un Nématode libre nouveau de la mer Caspienne, Chromadorissa gen. nov. (Chromadoridae, Chromadorini). (in Russian with French Abstract). Zoologichesky Zhurnal, 2, 24–30.

Filipjev, I. (1918) Free-living marine nematodes of the Sevastopol Area (translated from Russian). Part I Trudy Osob. Zoo/, Lab. Sevastopol. Biol. Stantsii Ross. Akad. Nauk, 2, 4, 1–352. Israel Program for Scientific translations (1969).

Filipjev, I. (1929) Classification of freeliving Nematoda and relations to parasitic forms. The Journal of Parasitology, 15, 281–282.

Filipjev, I.N. & Stekhoven, J.S. (1941) A manual of agriculture helmintology. E. Brill, Leiden, The Nederlands. 878 pp.

Genio, L., Johnson, S.B., Vrijenhoek, R.C., Cunha, M.R., Tyler, P.A., Kiel, S. & Little, C.T.S (2008) New record of "Bathymodiolus" mauritanicus Cosel 2002 from the Gulf of Cádiz (NE Atlantic) mud volcanoes. Journal of Shellfish Research, 27, 53–61.[53:NROBMC]2.0.CO;2

Gerlach, S.A. (1950) Die Diplopeltiden, eine Grouppe freilebender Nematoden. Kieler Meeresforsch, 7, 138–156.

Gerlach, S.A. (1956) Diagnosen neuer Nematoden aus der Kieler Butch. Kieler Meeresforsch,12, 85–109.

Gerlach, S.A. & Riemann, F. (1973) The Bremerhaven Checklist of Aquatic Nematodes. A catalogue of Nematoda Adenophorea excluding the Dorylaimida. Veröffentlichungen des Instituts für Meeresforschung in Bremerhaven Supplementband, 4, 1–736.

Gourbault, N. & Vincx, M. (1998) Calomicrolaimus compridus (Gerlach, 1956) n.comb., a marine nematode with a female producing a copulatory plug. Revue de Nématologie, 11, 39–43.

Guilini, K., Levin, L.A. & Vanreusel, V. (2012) Cold seep and oxygen minimum zone associated sources of margin heterogeneity affect benthic assemblages, diversity and nutrition at the Cascadian margin (NE Pacific Ocean). Progress in Oceanography, 96, 77–92.

Hauquier, F., Ingels, J., Gutt, J., Raes, M. & Vanreusel, A. (2011) Characterisation of the Nematode Community of a Low-Activity Cold Seep in the Recently Ice-Shelf Free Larsen B Area, Eastern Antarctic Peninsula. Plos One, 6.

Hope, W.D. & Murphy, D.G. (1972) A taxonomic hierarchy and checklist of the genera and higher taxa of marine nematodes. Smithsonian Contributions to Zoology, 137, 1–101.

Ingels, J., Tchesunov, A.V. & Vanreusel, A. (2011) Meiofauna in the Gollum Channels and the Whittard Canyon, Celtic Margin-How Local Environmental Conditions Shape Nematode Structure and Function. Plos One, 6.

Inglis, W.G. (1983) An outline classification of the phylum Nematoda. Australian Journal of Zoology, 31, 243–255.

Jensen, P. (1985) The nematode fauna in the sulfide-rich brine seep and adjacent bottoms of the East Flower Garden, NW Gulf of Mexico.1. Chromadorida. Zoologica Scripta, 14, 247–263.

Jensen, P. (1986) The nematode fauna in the sulfide-rich brine seep and adjacent bottoms of the East Flower Garden, NW Gulf of Mexico.4. Ecological aspects. Marine Biology, 92, 489–503.

Jensen, P. (1987) Differences in microhabitat, abundance, biomass and body size between oxybiotic and thiobiotic free-living marine nematodes. Oecologia, 71, 564–567.

Jensen, P. (1994) Rerision of Ethmolaiminae Filipjev and Stekhoven, 1941 (Nematoda, Chromadorida) with descriptions of one genus and 3 new species. Hydrobiologia, 286, 1–15.

Khera, S. (1975) On some nematodes belonging to the orders Chromadorida and Enoplida from India. Records of the Zoological Survey of India, 68, 273–286.

Levin, L.A. (2005) Ecology of cold seep sediments: Interactions of fauna with flow, chemistry and microbes. Oceanography and Marine Biology - an Annual Review, 43, 1–46.

Levin, L.A., Ziebis, W., Mendoza, G.F., Growney, V.A., Tryon, M.D., Brown, K.M., Mahn, C., Gieskes, J.M. & Rathburn, A.E. (2003) Spatial heterogeneity of macrofauna at northern California methane seeps: influence of sulfide concentration and fluid flow. Marine Ecology Progress Series, 265, 123–139.

Lins, L.Vanreusel, A., van Campenhout, J. & Ingels, J. (2013) Selective settlement of deep-sea canyon nematodes after resuspension – an experimental approach. Journal of Experimental Marine Biology and Ecology, 44, 110–116.

Lorenzen, S. (1994). (Lorenzen 1981) The phylogenetic sytematics of free-living nematodes. Ray Society, 383 pp.

Muthumbi, A.W., Soetaert, K. & Vincx, M. (1997) Deep-sea nematodes from the Indian Ocean: new and known species of the family Comesomatidae. Hydrobiologia, 346, 25–57.

Niemann, H., Fischer, D., Graffe, D., Knittel, K., Montiel, A., Heilmayer, O., Nothen, K., Pape, T., Kasten, S., Bohrmann, G., Boetius, A & Gutt, J. (2009) Biogeochemistry of a low-activity cold seep in the Larsen B area, western Weddell Sea, Antarctica. Biogeosciences, 6, 2383–2395.

Pape, E., Bezerra, T.N., Vanneste, H., Heeschen, K., Moodley, L., Leroux, F., Leroux, F., van Breugel, P. & Vanreusel, A. (2011) Community structure and feeding preference of nematodes associated with methane seepage at the Darwin mud volcano (Gulf of Cádiz). Marine Ecology Progress Series, 438, 71–83.

Pearse, A.S. (1942) An introduction to parasitology. Charles C. Thomas, Baltimore, 375 pp.

Pinheiro, L.M., Ivanov, M.K., Sautkin, A., Akhmanov, G., Magalhaes, V.H., Volkonskaya, A., Monteiro, J.H., Somoza, L., Gardner, J., Hamouni, N. & Cunha, M.R. (2003) Mud volcanism in the Gulf of Cádiz: results from the TTR-10 cruise. Marine Geology, 195, 131–151.

Platt, H.M. (1982) Revision of the Ethmolaimidae (Nematoda: Chromadorida). British Museum (Natural History), 251 pp.

Platt, H.M. (1985) Further observations on the Ethmolaimidae (Nematoda, Chromadorida). Journal of Natural History, 19, 139–149.

Raes, M & Rose, A. (2007) ANT-XXIII/8 (2006-2007) Sampling Report.

Schratzberger, M., Bolam, S.G., Whomersley, P., Warr, K. & Rees, H.L. (2004) Development of a meiobenthic nematode community following the intertidal placement of various types of sediment. Journal of Experimental Marine Biology and Ecology, 303, 79–96.

Shirayama, Y. & Ohta, S. (1990) Meiofauna in a cold-seep community off Hatsushima, Central Japan. Journal of Oceanography, 46, 118–124.

Soetaert, K., Muthumbi, A. & Heip, C. (2002) Size and shape of ocean margin nematodes: morphological diversity and depth-related patterns. Marine Ecology Progress Series, 242, 179–193.

Somoza, L., Diaz-del-Rio, V., Leon, R., Ivanov, M., Fernandez-Puga, M.C., Gardner, J.M., Hernandez-Molina, F.J., Pinheiro, L.M., Roderro, J., Lobato, A., Maestro, A., Vazquez, J.T., Medialdea, T. & Fernandez-Salas, L.M. (2003) Seabed morphology and hydrocarbon seepage in the Gulf of Cádiz mud volcano area: Acoustic imagery, multibeam and ultra-high resolution seismic data. Marine Geology, 195, 153–176.

Tchesunov, A.V., Ingels, J. & Popova, E.V. (2012) Marine free-living nematodes associated with symbiotic bacteria in deep-sea canyons of north-east Atlantic Ocean. Journal of the Marine Biological Association of the United Kingdom, 92, 1257–1271.

Van Dover, C.L., German, C.R., Speer, K.G., Parson, L.M. & Vrijenhoek, R.C. (2002) Marine biology - Evolution and biogeography of deep-sea vent and seep invertebrates. Science, 295, 1253–1257.

Van Gaever, S., Galeron, J., Sibuet, M. & Vanreusel, A. (2009) Deep-sea habitat heterogeneity influence on meiofaunal communities in the Gulf of Guinea. Deep-Sea Research Part Ii-Topical Studies in Oceanography, 56, 2259–2269.

Van Gaever, S., Moodley, L., de Beer, D. & Vanreusel, A. (2006) Meiobenthos at the Arctic Hakon Mosby Mud Volcano, with a parental-caring nematode thriving in sulphide-rich sediments. Marine Ecology Progress Series, 321, 143–155.

Van Rensbergen, P., Depreiter, D., Pannemans, B., Moerkerke, G., Van Rooij, D., Marsset, B., Akhmanov, G., Blinova, V., Ivanov, M., Rachidi, M., Magalhaes, V. Pinheiro, L., Cunha, M. & Henriet, J.-P. (2005) The El arraiche mud volcano field at the Moroccan Atlantic slope, Gulf of Cádiz. Marine Geology, 219, 1–17.

Vanneste, H., Kastner, M., James, R.H., Connelly, D., Fisher, R.E., Heeschen, K., Kelly-Gerreyn, B.A., Haeckel, M., Mills, R.A. (2012) Authigenic Carbonates from the Darwin Mud Volcano, Gulf of Cádiz: a Record of Palaeo-Seepage of Hydrocarbon Bearing Fluids. Chemical Geology, 300–301, 24–39.

Vanreusel, A., Andersen, A.C., Boetius, A., Connelly, D., Cunha, M.R., Decker, C., Ana, H, Konstantinos, K. Ar., Lois, M., Karine, O., Maria, P., Benedicte, R., Clara, R., Jozee, S., Paul, T., Saskia, V.G. & Heleen, V. (2009) Biodiversity of Cold Seep Ecosystems Along the European Margins. Oceanography, 22, 110–127.

Vanreusel, A., De Groote, A., Gollner, S. & Bright, M. (2010) Ecology and Biogeography of Free-Living Nematodes Associated with Chemosynthetic Environments in the Deep Sea: A Review. Plos One, 5.

Vanreusel, A., Fonseca, G., Danovaro, R., da Silva, M.C., Esteves, A.M., Ferrero, T., Gunnar, G., Valentina, G., Cristina, G., Da Fonseca, G.V., Jeroen, I., Baban, I., Nikolaos, L., Bea1, M., Dmitry, M., Maria, M., Agnes, M., Sergio, M., Daria, P., Teresa, P., Maarten, R., Alexei, T., Jan, V., Saskia1, V.G., Virag, V., Nara1, B.T., Hannah, F., John, C., Ellen, p., Daniela, P., Arbizu, M.P. & Joelle, G. (2010) The contribution of deep-sea macrohabitat heterogeneity to global nematode diversity. Marine Ecology-an Evolutionary Perspective, 31, 6–20.

Villares, G., Martelli, A., Lo Russo, V. & Pastor, C. (2013) Three new species and one new record of Campylaimus (Diplopeltidae, Nematoda) from Argentine coasts (Buenos Aires and Santa Cruz, Argentina). Zootaxa, 3613(1), 83–96.

Vincx, M. & Gourbault, N. (1988) Two new species of Morlaixia (Nematoda: Diplopeltidae) with a subterminal ventral mouth. Bulletin du muséum national d’Histoire naturelle, Paris (4ième série), 10, 711–718.

Warwick, R.M., Platt, H.M. & Somerfield, P.J. (1998) Free-living marine nematodes part III Monhysterids: pictorial key to world genera and notes for the identification of British species. Synopses of the British fauna (New Series) 53. Field Studies Council: Shrewsbury, UK, 296 pp.

Wieser, W. & Hopper, B. (1966) Neotonchinae new Subfamily (Cyatholaimidae – Nematoda) with an analysis of its genera Neotonchus Cobb, 1933 and Gomphionema New Genus. Canadian Journal of Zoology, 44, 519–532.

Zeppilli, D., Canals, M. & Danovaro, R. (2012) Pockmarks enhance deep-sea benthic biodiversity: a case study in the western Mediterranean Sea. Diversity and Distributions, 18, 832–846.

Zeppilli, D. & Danovaro, R. (2009) Meiofaunal diversity and assemblage structure in a shallow-water hydrothermal vent in the Pacific Ocean. Aquatic Biology, 5, 75–84.

Zeppilli, D., Mea, M., Corinaldesi, C. & Danovaro, R. (2011) Mud volcanoes in the Mediterranean Sea are hot spots of exclusive meiobenthic species. Progress in Oceanography, 91, 260–272.


  • There are currently no refbacks.

ISSN 1175-5326 (Print Edition) & ISSN 1175-5334 (Online Edition)
Published by Magnolia Press, Auckland, New Zealand
A founding journal of Biotaxa