Higher Classification: > Kingdom Animalia > Subkingdom Eumetazoa > Phylum Nematoda > Class Chromadorea > Subclass Chromadoria > Order Monhysterida > Suborder Monhysterina > Superfamily Sphaerolaimoidea > Family Xyalidae

Theristus Bastian, 1865

Rank: Genus
Taxon Status: accepted

Relationships towards this taxon

Genus group names

*Penzancia*	de Man, 1889	synonym
*Theristus (Penzancia)*	de Man, 1889	synonym

Children

Theristus acer Bastian, 1865
Theristus acriformis (de Man, 1922) Gerlach & Riemann, 1973
Theristus aculeatus Schulz, 1935
Theristus agilis (de Man, 1880)
Theristus anisocirculus Blome, 1982
Theristus anisotrichus Lorenzen, 1971
Theristus athesinus Andrássy, 1962
Theristus balticus Lorenzen, 1973
Theristus bastiani Gerlach & Riemann, 1973
Theristus bipunctatus (Schneider, 1906) Gerlach & Riemann, 1973
Theristus blandicor Rachor, 1971
Theristus complexus Jayasree & Warwick, 1977
Theristus denticulatus Warwick, 1970
Theristus ensifer Gerlach, 1951
Theristus flevensis Schuurmans Stekhoven, 1935
Theristus gracilis (de Man, 1876) Filipjev, 1918
Theristus helveticus (Steiner, 1914)
Theristus heterospiculoides Gerlach, 1953
Theristus heterospiculum (Allgén, 1932) Gerlach, 1953
Theristus inermis Gerlach, 1953
Theristus interstitialis Warwick, 1970
Theristus latissimus (Filipjev, 1922)
Theristus leptosoma Allgén, 1950
Theristus lineatus Gerlach, 1965
Theristus littoralis Filipjev, 1922
Theristus longicollis Blome, 1982
Theristus longisetosus Schuurmans Stekhoven & De Coninck, 1933
Theristus longus Platt, 1973
Theristus macer Lorenzen, 1973
Theristus meyli Riemann, 1966
Theristus monstrosus Gerlach, 1954
Theristus norwegicus (Allgén, 1933) Wieser, 1956
Theristus obtusicephalus Schuurmans Stekhoven, 1950
Theristus otoplanobius Gerlach, 1951
Theristus pannonicus Andrássy, 1985
Theristus parasetosus (Allgén, 1928)
Theristus pellucidus Allgén, 1939
Theristus pertenuis Schuurmans Stekhoven, 1935
Theristus pictus Gerlach, 1951
Theristus problematicus (Allgén, 1927) Wieser, 1956
Theristus profundus Blome, 1982
Theristus pyronasi Gerlach, 1965
Theristus rhynchonemoides Hopper, 1961
Theristus roscoffiensis Vitiello, 1967
Theristus ruffoi Andrássy, 1959
Theristus sabulicola (Filipjev, 1918) Wieser, 1956
Theristus scanicus Allgén, 1949
Theristus stichotricha Schuurmans Stekhoven, 1950
Theristus strandi Allgén, 1934
Theristus tenuicaudatus Allgén, 1951
Theristus terricola (Andrássy, 1985)
Theristus velox Bastian, 1865
Theristus vesentiniae Andrássy, 1962
Theristus wegelinae Andrássy, 1962

Literature

original description	Bastian, H. C. (1865). Monograph of the Anguillulidae, or Free Nematoids, Marine, Land, and Freshwater; with Descriptions of 100 New Species. The Transactions of the Linnean Society of London. Volume XXV. Part II:73-184.
basis of record	Nemaslan: Biodiversity of Antarctic Nematodes (2004).
additional source	Heip, C.; Decraemer, W. (1974). The diversity of nematode communities in the Southern North Sea. J. mar. biol. Ass. U. K. 54: 251-255.
additional source	Fonseca, G.; Soltwedel, T.; Vanreusel, A.; Lindegarth, M. (2010). Variation in nematode assemblages over multiple spatial scales and environmental conditions in Arctic deep seas. Progress in Oceanography. 84 (3-4): 174-184.
additional source	Zekely, J.; Van Dover, C.; Nemeschkal, H.; Bright, M. (2006). Hydrothermal vent meiobenthos associated with mytilid mussel aggregations from the Mid-Atlantic Ridge and the East Pacific Rise. Deep Sea Research Part I: Oceanographic Research Papers. 53(8): 1363-1378.
additional source	De Oliveira Pinto, T.K.,Netto, S.A., Esteves, A.M., De Castro, F.J.V., Neres, P.F. and Da Silva, M.C. (2021). Free-living freshwater nematodes from Brazil: checklist of genera and regional patterns of diversity. Nematology. 0 (2021) 1-14.
additional source	Dando, P. R.; Austen, M. C.; Burke, Jr. R. A.; Kendall, M. A.; Kennicutt, II M. C.; Judd, A. G.; Moore, D. C.; O'Hara, S. C. M.; Schmaljohann, R.; Southward, A. J. (1991). Ecology of a North Sea pockmark with an active methane seep. Marine Ecology Progress Series. 70: 49-63.
additional source	Van Gaever, S.; Moodley, L.; De Beer, D.; Vanreusel, A. (2006). Meiobenthos at the Arctic Håkon Mosby Mud Volcano, with a parental-caring nematode thriving in sulphide-rich sediments. Marine Ecology Progress Series. 321: 143-155.
additional source	Timm, R. W. (1957). New Marine Nematodes from St. Martin's Island. Pakist. J. Scient. Res., 9 (4): 133-138
additional source	Li, J.; Vincx, M. (1993). The temporal variation of intertidal nematodes in the Westerschelde. I. The importance of an estuarine gradient. Netherlands Journal of Aquatic Ecology. 27 (2-4): 319-326.
additional source	Armenteros, M.; Vincx, M.; Decraemer, W. (2010). Guitartia tridentata n. gen., n. sp. (Monhysterida: Xyalidae) and Macrodontium gaspari n. gen., n. sp. (Chromadorida: Microlaimidae), free-living marine nematodes from the Caribbean Sea. Nematology. 12 (3): 417-427.
additional source	Derycke, S.; Van Vynckt, R.; Vanaverbeke, J.; Vincx, M.; Moens, T. (2007). Colonization patterns of Nematoda on decomposing algae in the estuarine environment: community assembly and genetic structure of the dominant species Pellioditis marina. Limnology and Oceanography. 52(3): 992-1001.
additional source	Sebastian, S.; Raes, M.; De Mesel, I.; Vanreusel, A. (2007). Comparison of the nematode fauna from the Weddell Sea Abyssal Plain with two North Atlantic abyssal sites. Deep Sea Research Part II: Topical Studies in Oceanography. 54(16-17): 1727-1736.
additional source	Copley, J. T. P.; Flint, H. C.; Ferrero, T. J.; Van Dover, C. L. (2007). Diversity of meiofauna and free-living nematodes in hydrothermal vant mussel beds on the northern and southern East Pacific Rise. J. Mar. Biol. Ass. U.K.
additional source	Maria, T. F.; Esteves, A. M.; Smol, N.; Vanreusel, A.; Decraemer, W. (2008). Nematodes from sandy beaches of Guanabara Bay, Rio de Janeiro, Brazil. Biociências, Porto Alegre. 16 (2), 92-103.
additional source	Maria, T. F.; Esteves, A. M.; Vanaverbeke, J.; Vanreusel, A. (2013). Is nematode colonisation in the presence of Scolelepis in tropical sandy-beach sediment similar to the colonisation process in temperate sandy beaches?. Braz. J. Biol. 73(1): 19-28.
additional source	Maria, T. F.; Vanaverbeke, J.; Esteves, A. M.; De Troch, M.; Vanreusel, A. (2012). The importance of biological interactions for the vertical distribution of nematodes in a temperate ultra-dissipative sandy beach. Estuarine, Coastal and Shelf Science. 97: 114-126.
additional source	Van Gaever, S.; Galéron, 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(23): 2259-2269.
additional source	de Leonardis, C., R. Sandulli, J. Vanaverbeke, M. Vincx & S. de Zio. (2008). Meiofauna and nematode diversity in some Mediterranean subtidal areas of the Adriatic and Ionian Sea. Scientia Marina Barcelona (Spain). .72 (1): 5-13.
additional source	Mahmoudi, E.; Essid, N.; Beyrem, H.; Hedfi, A.; Boufahdja, F.; Aïssa, P.; Vitiello, P. (2008). Mussel-farming effects on Mediterranean benthic nematode communities. Nematology. 10 (3): 323-333.
additional source	Decraemer, W.; Coomans, A. (1978). Scientific Report on the Belgian Expedition to The Great Barrier Reef in 1967. Nematodes XII. Ecological Notes on the Nematode Fauna in and around Mangroves on Lizard Island. Aust. J. Mar. Freshwater Res. 29, 497-508.
additional source	Vanaverbeke, J., K. Soetaert, C. Heip & A. Vanreusel. (1997). The metazoan meiobenthos along the continental slope of the Goban Spur (NE Atlantic). Journal of Sea Research. 38:93-107.
additional source	Zekely, J.; Gollner, S.; Van Dover, C. L.; Govenar, B.; Le Bris, N.; Nemeschkal, H. L.; Bright, M. (2006). Nematode communities associated with tubeworm and mussel aggregations on the East Pacific Rise. Cah. Biol. Mar. 47: 477-482.
additional source	Miljutin, D. M.; Gad, G.; Miljutina, M. M.; Mokievsky, V. O.; Fonseca-Genevois, V.; Esteves, A. M. (2010). The state of knowledge on deep-sea nematode taxonomy: how many valid species are known down there?. Marine Biodiversity. 40(3): 143-159.
additional source	Vanreusel, A.; Fonseca, G.; Danovaro, R.; Da Silva, M. C.; Esteves, A. M.; Ferrero, T.; Gad, G.; Galtsova, V.; Gambi, C.; Da Fonsêca Genevois, V.; Ingels, J.; Ingole, B.; Lampadariou, N.; Merckx, B.; Miljutin, D.; Miljutina, M.; Muthumbi, A.; Netto, S.; Portnova, D.; Radziejewska, T.; Raes, M.; Tchesunov, A.; Vanaverbeke, J.; Van Gaever, S.; Venekey, V.; Bezerra, T. N.; Flint, H.; Copley, J.; Pape, E.; Zeppilli, D.; Martinez, P. A.; Galeron, J. (2010). The contribution of deep-sea macrohabitat heterogeneity to global nematode diversity. Marine Ecology. 31(1): 6-20.
additional source	Brunel, P., L. Bosse & G. Lamarche. (1998). Catalogue of the marine invertebrates of the estuary and Gulf of St. Lawrence. Canadian Special Publication of Fisheries and Aquatic Sciences, 126. 405 pp.
additional source	Verschelde, D.; Nicholas, W.; Vincx, M. (2006). A Review of the Genera Croconema Cobb, 1920 and Pseudochromadora Daday, 1899 (Nematoda, Desmodoroidea): New Species from the Coasts of Kenya and Australia. Hydrobiologia. 571, 17-40.
additional source	Lorenzen, S. (1977). Revision der Xyalidae (freilebende Nematoden) auf der Grundlage einer kritischen Analyse von 56 Arten aus Nord- und Ostsee. Veroff. Inst. Meeresforsch. Bremerh. 16: 197-261.
additional source	Heip, C.; Herman, R.; Vincx, M. (1983). Subtidal meiofauna of the North Sea: A review. Biol. Jb. Dodonaea. 51: 116-170.
additional source	Pastor de Ward, C. T. (1985). Nematodes de la Ria Deseado (Monhysteroidea, Xyalidae), Santa Cruz, Argentina. II. Physis. Secc. A, 43 (105): 113 - 130.
additional source	Zeppilli, D. & R. Danovaro (2009). Meiofaunal diversity and assemblage structure in a shallow-water hydrothermal vent in the Pacific Ocean. Aquatic Biology. 5(1):75-84.
additional source	Venekey, V.; Fonseca-Genevois, V.; Santos, P. J. P. (2010). Biodiversity of free-living marine nematodes on the coast of Brazil: a review. Zootaxa. 2568: 39–66.
additional source	Van Gaever, S.; Olu, K.; Derycke, S.; Vanreusel, A. (2009). Metazoan meiofaunal communities at cold seeps along the Norwegian margin: Influence of habitat heterogeneity and evidence for connection with shallow-water habitats. Deep Sea Research Part I: Oceanographic Research Papers. 56(5): 772-785.
additional source	Integrated Taxonomic Information System (ITIS).
additional source	Armenteros, M.; Vincx, M.; Decraemer, W. (2009). Cienfuegia gen. nov. (Xyalidae) and Pseudoterschellingia gen. nov. (Linhomoeidae), two new genera of free-living marine nematodes from the Caribbean Sea. Journal of Natural History. 43(17-18): 1067-1081.
taxonomy source	Venekey, V.; Gheller, P. F.; Maria, T. F.; Brustolin, M. C.; Kandratavicius, N.; Vieira, D. C.; Brito, S.; Souza, G. S.; Fonseca, G. (2014). The state of the art of Xyalidae (Nematoda, Monhysterida) with reference to the Brazilian records. Marine Biodiversity. 44(3): 367-390.
ecology source	Raes, M.; Vanreusel, A. (2006). Microhabitat type determines the composition of nematode communities associated with sediment-clogged cold-water coral framework in the Porcupine Seabight (NE Atlantic). Deep-Sea Research Part I. 53 (12): 880-1894.
ecology source	Fonsêca-Genevois, V.da., P.J. Somerfield, M.H. Baeta-Neves, R. Coutinho & T. Moens. (2006). Colonization and early succession on artificial hard substrata by meiofauna. Marine Biology 148(5):1039-1050.
ecology source	Ingels, J., K. Kiriakoulakis, G.A. Wolff & A. Vanreusel. (2009). Nematode diversity and its relation to the quantity and quality of sedimentary organic matter in the deep Nazaré Canyon, Western Iberian Margin. Deep Sea Research Part I: Oceanographic Research Papers. 56(9): 1521-1539.
ecology source	Raes, M.; De Troch, M.; Ndaro, S. G. M.; Muthumbi, A.; Guilini, K.; Vanreusel, A. (2007). The structuring role of microhabitat type in coral degradation zones: a case study with marine nematodes from Kenya and Zanzibar. Coral Reefs. 26 (1): 13-126.
ecology source	Maria, T. F.; Vanaverbeke, J.; Esteves, A. M.; De Troch, M.; Vanreusel, A. (2012). The importance of biological interactions for the vertical distribution of nematodes in a temperate ultra-dissipative sandy beach. Estuarine, Coastal and Shelf Science. 97: 114-126.
identification resource	Tu, N. D.; Gagarin, V. G. (2017). Free-living nematodes from mangrove forest in the Yên River estuary (Vietnam). Inland Water Biology. 10(3): 266-274.

Genbank

Taxonomy

NeMys
NeMys

Citation

Nemys eds. (2025). Nemys: World Database of Nematodes. Theristus Bastian, 1865. Via: Costello, M.J.; Bouchet, P.; Boxshall, G.; Arvantidis, C.; Appeltans, W. (2011) European Register of Marine Species, Accessed through PESI at http://www.eu-nomen.eu/portal/taxon.php?GUID=urn:lsid:marinespecies.org:taxname:2469

Dr. Vlada Peneva. Theristus Bastian, 1865. Accessed through: Fauna Europaea at https://portal.cybertaxonomy.org/fauna-europaea/cdm_dataportal/taxon/793a6b5f-cccc-481e-93fa-c8664e149284