Abstract
Morphological descriptions of two species of the genus Theristus Bastian, 1865 belonging to group flevensis, found in the hypersaline water bodies of the Crimean Peninsula, are presented. Theristus siwaschensis sp. n. is morphologically closest to T. flevensis Schuurmans Stekhoven, 1935, T. parambronensis Timm, 1952, T. macroflevensis Gerlach, 1954, T. metaflevensis Gerlach, 1955, but differs from them by the structure of the reproductive system in females, number of cephalic setae and size of spicules. Specimens of T. flevensis found in the Lake Chersonesskoye are similar to the re-description of a large forms of T. flevensis from Chile by Murhy (1966) and Caspian Sea by Chesunov (1981). However, it differs from the Caspian Sea species by having larger amphids, longer cephalic setae and spicules. T. pratti Murph & Canaris, 1964 and T. ambronensis Schulz, 1937 are synonymized with T. flevensis.
References
Abebe, E., Decraemer, W. & De Ley, P. (2008) Global diversity of nematodes (Nematoda) in freshwater. In Freshwater Animal Diversity Assessment. Hydrobiologia, 595, 67–78.
https://doi.org/10.1007/s10750-007-9005-5
Al-Thani, R., Al-Najjar, M.A., Al-Raei, A.M., Ferdelman, T., Thang, N.M., Al Shaikh, I., Al-Ansi, M. & de Beer, D. (2014) Community structure and activity of a highly dynamic and nutrient-limited hypersaline microbial mat in Um Alhool Sabkha, Qatar. PLoS ONE, 9 (3), e92405.
https://doi.org/10.1371/journal.pone.0092405
Anufriieva, E., Hołyńska, M. & Shadrin, N. (2014) Current invasions of Asian Cyclopid species (Copepoda: Cyclopidae) in Crimea, with taxonomical and zoogeographical remarks on the hypersaline and freshwater fauna. Annales Zoologici, 64 (1), 109–130.
https://doi.org/10.3161/000345414X680636
Anufriieva, E.V., Vdodovich, I.V. & Shadrin, N.V. (2018) First data on predation of Eucypris mareotica (Crustacea, Ostracoda) in hypersaline waters. Food Webs, 16, e00090.
https://doi.org/10.1016/j.fooweb.2018.e00090
Bezerra, T.N., Decraemer, W., Eisendle-Flöckner, U., Hodda, M., Holovachov, O., Leduc, D., Miljutin, D., Mokievsky, V., Peña Santiago, R., Sharma, J., Smol, N., Tchesunov, A., Venekey, V., Zhao, Z. & Vanreusel, A. (2020) Nemys: World Database of Nematodes. Available from: http://nemys.ugent.be (accessed 17 April 2020)
Danovaro, R., Gambi, C., Dell’Anno, A., Corinaldesi, C., Fraschetti, S., Vanreusel, A., Vincx, M. & Gooday, A.J. (2008) Exponential decline of deep-sea ecosystem functioning linked to benthic biodiversity loss. Current Biology, 18 (1), 1–8.
https://doi.org/10.1016/j.cub.2007.11.056
Feazel, L.M., Spear, J.R., Berger, A.B., Harris, J.K., Frank, D.N., Ley, R.E. & Pace, N.R. (2008) Eucaryotic diversity in a hypersaline microbial mat. Applied and Environmental Microbiology, 74, 329–332.
https://doi.org/10.1128/AEM.01448-07
Fonseca, G. & Bezerra, T.N. (2014) Order Monhysterida. Filipjev, 1929. In: Schmidt-Rhaesa, A. (Ed.), Handbook of zoology. 1st Edition. De Gruyter, Berlin, pp. 435–465.
https://doi.org/10.1515/9783110274257.435
Gerlach, S. (1951) Freilebende Nematoden aus der Verwandfschaft der Gattung Theristus. Zoologische Jahrbücher, Abteilung für Systematik, Geographie und Biologie der Tiere, 80, 379–398.
Gerlach, S.A. (1954) Freilebende Nematoden aus der Lagoa Radrigo de freitas (Rio de Janero). Zoologischer Anzeiger, 153, 135–143.
Gerlach, S. (1955) Zur Kenntnis der freilebenden marinen Nematoden von san Salvador. Zeitschrift für wissenschaftliche Zoologie, 158, 249–303.
Gerlach, S. (1957) Marine Nematoden aus dem MangroveGebiet von Cananeia (Brasilische Meeres Nematoden III). Akademie der Wissenschaften und Literatur, Mainz, Abhandlungen der Mathemathik-naturwissenschaftlichen Klasse, 5, 129–176.
Gerlach, S.A. (1965) Freilebende Meersenematoden aus der Gezeitenzone von Spitzbergen. Veröffentlichungen des Instituts für Meeresforschungen in Bremerhaven, Band IX, 109–172.
Gerlach, S.A. (1967) Freilebende Meeres-Nematoden von den Sarso-Inseln (Rotes Meer). Meteor-Forschungsergebnisse (D), 2, 19–43.
Kolesnikova, E.A., Mazlumyan, S.A. & Shadrin, N.V. (2008) Seasonal dynamics of meiobenthos fauna from a salt lake of the Crimea (Ukraine). In: Environmental micropaleontology, microbiology and meiobenthology EMMM’2008: first international conference, University of Madras, Chennai, India, 17 February 2008, pp. 155–158.
Mengistou, S. (2016) Invertebrates of East African Soda lakes. In: Schagerl, M. (Ed.), Soda lakes of East Africa. Springer, Cham, pp. 205–226.
https://doi.org/10.1007/978-3-319-28622-8_8
Murphy, D.G. & Canaris, A.G. (1965) Theristus pratti n. sp., a marine nematode from Kenya. Proceedings of the Helminthological Society of Washington, 31 (2), 203–208.
Murphy, D.G. (1966) An initial report on a collection of Chilean marine nematodes. Mitteilungen Aus Dem Hamburgischen Zoologische Museum Und Institut, 63, 29–50.
Ólafsson, E., Carlstrom, S. & Ndaro, S.G.M. (2000) Meiobenthos of hypersaline tropical mangrove sediment in relation to spring tide inundation. Hydrobiologia, 426, 57–64.
https://doi.org/10.1007/978-94-011-4148-2_5
Riemann, F. (1966) Die interstitielle Fauna im Elbe-Aestuar. Verbreitung und Systematik. Archiv fur Hydrobiologie, Supplement XXXI, 1/2, 1–279.
Schulz, E. (1937) Das Farbstreifen-Sandwatt und seine Fauna, eine ökologische-biozönotische Untersuchung an der Nordsee. Meereskundliche Arbeiten der Universität Kiel, 19, 359–378.
Sergeeva, N.G. (1981) New species of the genus Campylaimus (Nematoda, Araeolaimida) from the Black Sea and Sivash Lake. Zoologichesky Zhurnal, 60, 1717–1719.
Sergeeva, N.G., Gooday, A.J., Mazlumyan, S.A., Kolesnikova, E.A., Lichtschlag, A., Kosheleva, T.N. & Anikeeva, O.V. (2012) Meiobenthos of the oxic/anoxic interface in the Southwestern region of the Black Sea: abundance and taxonomic composition. In: Altenbach, A.V., Bernhard, J.M. & Seckbach, J. (Eds.), Anoxia: paleontological strategies and evidence for eukaryotes Survival. Springer, Dordrecht, pp. 369–401.
https://doi.org/10.1007/978-94-007-1896-8_20
Sergeeva, N.G., Shadrin, N.V. & Anufriieva, E.V. (2019) Long-term changes (1979–2015) in the nematode fauna in Sivash Bay (Sea of Azov), Russia, worldwide the largest hypersaline lagoon, during salinity transformations. Nematology, 21 (4), 337–347.
https://doi.org/10.1163/15685411-00003217
Shadrin, N.V., Sergeeva, N.G., Latushkin, A.A., Kolesnikova, E.A., Kipriyanova, L.M., Anufriieva, E.V. & Chepyzhenko, A.A. (2016) Transformation of Gulf Sivash (the Sea of Azov) in conditions of growing salinity: Changes of meiobenthos and other ecosystem components (2013–2015). Journal of Siberian Federal University, Biology, 9, 452–466.
https://doi.org/10.17516/1997-1389-2016-9-4-452-466
Shadrin, N.V., Anufriieva, E.V., Kipriyanova, L.M., Kolesnikova, E.A., Latushkin, A.A., Romanov, R.E. & Sergeeva, N.G. (2018) The political decision caused the drastic ecosystem shift of the Sivash Bay (the Sea of Azov). Quaternary International, 475, 4–10.
https://doi.org/10.1016/j.quaint. 2017.12.009
Tchesunov, A.V. (1981) Free-living nematodes of the group of Theristus flevensis (Monhysterida) species in the Caspian Sea. Biulletin Moskovskogo Obshchestva Ispytatelei Prirody, Otdel Biologii, 86 (2), 63–70.
Timm, R.W. (1952) A survey of the marine Nematodes of Chesapeake Bay, Maryland. Chesapeake Biological Laboratory Publication Series/Contribution Series 95. Chesapeake Biological Laboratory, Solomons Island, Maryland, 70 pp.
Tsalolikhin, S. Ya. (1980) Free-Living Nematodes of Lake Baikal. Nauka, Novosibirsk, 119 pp.
Tsalolikhin, S. Ya. (2007) A review of the genus Geomonhystera (Nematoda, Monhysterida, Monhysteridae) with a description of the new species, G. taurica. Zoologichesky Zhurnal, 86, 1283–1289.
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.
https://doi.org/10.1134/S1995082917030129
Wieser, W. & Hopper, B. (1967) Marine nematodes of the east coast of North America. I. Florida, Bulletin of the Museum of Comparative Zoology at Harvard College, 135, 239–344.
Wiktor, J. & Szymelfenig, M. (2002) Patchiness of sympagic algae and meiofauna from the fast ice of North Open Water (NOW) Polynya. Polish Polar Research, 23, 175–184.
Zaki, M.J., Khan, D. & Abid, M. (2012) Nematodes in the saline environment: a mini overview. International Journal of Biology and Biotechnology, 9, 99–113.