Tatarocyclops dayanae — a new hyporheic genus and species of Cyclopidae (Copepoda, Cyclopoida) from the European part of Russia
Abstract
A new genus and species of Cyclopidae (Copepoda, Cyclopoida) from the hyporheic zone of small rivers in Tatarstan (Russia) is described. The diagnosis of Tatarocyclops dayanae gen. et sp. nov. includes: female antennule 11-segmented; first to fourth swimming legs with two-segmented exopods and endopods; endopod of the fourth leg with two apical spines; and fifth leg two-segmented, not fused to the somite. The new genus shares a two-segmented fifth leg with Reidcyclops Karanovic, 2000, but differs from it and from other genera of the Mixocyclops Kiefer, 1944 group by the following combination: mandibular palp with one seta; maxilliped armature formula 2.2.1.2; first swimming leg basis with inner spine; spine formula of the second exopodal segments of the first to fourth swimming legs 2.3.3.3; third swimming leg without sexual dimorphism; fourth swimming leg endopod with two apical spines; and distal segment of the fifth leg with two setae. Among Cyclopidae with 9–11-segmented antennules, Tatarocyclops gen. nov. is distinctly separated by its unique combination of characters, especially the two-segmented fifth leg. The discovery of a stygobiotic cyclopid genus in the Middle Volga region aligns with recent findings of endemic amphipods in the same area and highlights a previously unexplored diversity of groundwater fauna, which is important for understanding the biogeography of Palearctic freshwater crustaceans.
References
Alekseev V.R. & Arov I.V. 1986. Novyy tsiklop roda Diacyclops (Crustacea, Copepoda) iz eylitorali ozera Baykal. Zoologicheskii Zhurnal 65 (7): 1084–1088.
Apostolov A.M. 2010. Fauna Bulgarica 29. Copepoda, Harpacticoida. Editio Academica ‘Professor Marin Drinov’, Sofia.
Berdnik S.V., Tokinova R.P. & Galiahmetova L.K. 2024. Composition and quantitative indicators of meiobenthos in springs of Kazan and its environs. Hydrosphere Ecology 1 (11): 61–74. https://doi.org/10.33624/2587-9367-2024-1(11)-61-74
Boonyanusith C., Sanoamuang L. & Brancelj A. 2018. A new genus and two new species of cave-dwelling cyclopoids (Crustacea, Copepoda) from the epikarst zone of Thailand and up-to-date keys to genera and subgenera of the Bryocyclops and Microcyclops groups. European Journal of Taxonomy 431: 1–30. https://doi.org/10.5852/ejt.2018.43
Borutzky E.V. 1926. K faune podzemnyh vod: Parastenocaris fonticola sp. n. Trudy Kosinskoi Biologicheskoi Stantsii 4: 47–50.
Borutzky E.V. 1972a. Copepoda Harpacticoida gruntovykh vod poberezhya oz. Issyk-kul i yuzhnoi chasti Kyzylkumov. Fauna gruntovykh vod Srednei Azii 51: 98–119.
Borutzky E.V. 1972b. Copepoda Harpacticoida peshcher zapadnogo Zakavkaz’ya. Sbornik Trudov Zoologicheskogo Museya MGU 12: 37–60.
Boxshall G.A., Evstigneeva T.D. & Clark P.F. 1993. A new interstitial cyclopoid copepod from a sandy beach on the western shore of Lake Baikal, Siberia. Hydrobiologia 268 (2): 99–107. https://doi.org/10.1007/BF00006880
Brancelj A., Boonyanusith C. & Sanoamuang L. 2024. A new cyclopoid genus (Copepoda, Crustacea) from a deep aquifer in northeastern Thailand with comments on peculiar sampling sites and local fauna. Raffles Bulletin of Zoology 72: 71–83. https://doi.org/10.26107/RBZ-2024-0005
Chappuis P.A. 1917. Zur Kenntnis der Copepodenfauna von Surinam. I. Cyclopiden. Zoologischer Anzeiger 49 (7–8): 220–225. Available from https://www.biodiversitylibrary.org/page/30120650 [accessed 7 Jul. 2026].
Chappuis P.A. 1942. Eine neue Methode zur Untersuchung der Grundwasserfauna. Acta Scientifica der Mathematisch- Naturwissenschaftlichen Universität Francisco Josephinae Kolozsvar, Cluj 6: 1–7.
Chappuis P.A. 1951. Copépodes de Tasmanie. Archives de Zoologie expérimentale et générale 87 (Notes et revue 3): 104–115.
Coelho-Botelho M.J. 1999. Revisão do Gênero Apocyclops Lindberg, 1942 (Copepoda: Cyclopoida). Tese (Doutorado), Universidade de Sao Paulo.
Cottarelli V., Bruno M.C., Spena M.T., Caccamo D.V. & Grasso R. 2026. A new stygobitic genus and species of Cyclopinae (Crustacea, Copepoda, Cyclopoida), from the epikarst of Scrivilleri Cave, Sicily (Italy). Zootaxa 5845 (1): 1–27. https://doi.org/10.11646/zootaxa.5845.1.1
Damian A. 1957. Noi Copepode cavernicole. Buletin Stiintific 9 (2): 131–143.
De Laurentiis P., Pesce G.L. & Humphreys W.F. 2001. Copepods from ground waters of Western Australia, VI. Cyclopidae (Crustacea: Copepoda) from the Yilgarn region and the Swan coastal plain. Records of the Western Australian Museum Supplement 64: 115–131. https://doi.org/10.18195/issn.0313-122x.64.2001.115-131
Di Cicco M., Di Lorenzo T., Iannella M., Vaccarelli I., Galassi D.M.P. & Fiasca B. 2021. Linking hydrogeology and ecology in karst landscapes: the response of epigean and obligate groundwater copepods (Crustacea: Copepoda). Water 13 (15): 2106. https://doi.org/10.3390/w13152106
Dussart B.H. 1984. Sur quelques Crustacés Copépodes de Nouvelle-Calédonie. Revue d’Hydrobiologie Tropicale 17 (4): 301–308.
Einsle U. 1985. A further criterion for the identification of species in the genus Cyclops s. str. (Copepoda, Cyclopoida). Crustaceana 49 (347): 299–309. https://doi.org/10.1163/156854085x00611
Einsle U. 1993. Crustacea: Copepoda: Calanoida und Cyclopoida. In: Schwoerbel J. & Zwick P. (eds) Süsswasserfauna von Mitteleuropa Bd. 8/4–1. Gustav Fischer Verlag, Stuttgart.
Ferrari F.D. & Ivanenko V.N. 2008. The identity of protopodal segments and the ramus of maxilla 2 of copepods (Copepoda). Crustaceana 81 (7): 823–835. https://doi.org/10.1163/156854008784771702
Fiers F. 2001. Meridiecyclops, gen. nov., a new cyclopid genus (Crustacea: Copepoda: Cyclopidae) from southern Australia. Invertebrate Systematics 15 (6): 893–908. https://doi.org/10.1071/it01003
Fiers F. 2005. A new species of the genus Speocyclops (Crustacea, Copepoda, Cyclopoida) from the Han-sur-Lesse Cave, a well known and popular cavern, in southeastern Belgium. Bulletin de l’Institut royal des Sciences naturelles de Belgique, Biologie 75: 111–118.
Fiers F. 2011. Apalachocyclops gen. nov. (Copepoda, Cyclopoida, Cyclopidae): a nearctic “Doppelgänger” of the European speocyclopines. In: Studies on Freshwater Copepoda: A Volume in Honour of Bernard Dussart: 177–197. Brill. https://doi.org/10.1163/9789004188280_009
Fiers F. 2012. The generic concept of Allocyclops Kiefer, 1932: (Copepoda: Cyclopoida: Cyclopidae) an alternative view. Journal of Natural History 46 (3–4): 175–247. https://doi.org/10.1080/00222933.2011.626530
Fiers F. & Jocque M. 2013. Leaf litter copepods from a cloud forest mountain top in Honduras (Copepoda: Cyclopidae, Canthocamptidae). Zootaxa 3630 (2): 270–290. https://doi.org/10.11646/zootaxa.3630.2.4
Fiers F. & Pandourski I. 2008. Redescription of Speocyclops orcinus Kiefer, 1937 (Copepoda Cyclopoida Cyclopidae) from the type locality, Cave Iriberi, in southern France. Bulletin de l’Institut royal des Sciences naturelles de Belgique, Biologie 78: 5–16.
Fiers F. & Van Damme K. 2017. Thalamocyclops pachypes gen. nov., sp. nov. (Copepoda: Cyclopoida: Cyclopidae), a crevicular cyclopine from Socotra Island (Yemen): tale of a remarkable survival drive. Journal of Natural History 51 (41–42): 2463–2507. https://doi.org/10.1080/00222933.2017.1344328
Galassi D.M. 2001. Groundwater copepods: diversity patterns over ecological and evolutionary scales. Hydrobiologia 453 (1): 227–253. https://doi.org/10.1023/a:1013100924948
Galassi D.M.P. & De Laurentiis P. 2004. Little-known cyclopoids from groundwater in Italy: re-validation of Acanthocyclops agamus and redescription of Speocyclops italicus (Crustacea, Copepoda, Cyclopoida). Vie et Milieu 54 (4): 203–222.
Galassi D.M.P. & Pesce G.L. 1992. The genus Hesperocyclops Herbst: an update, and description of Hesperocyclops venezuelanus n. sp. from Venezuela (Crustacea Copepoda: Cyclopidae). Stygologia, Leiden 7 (4): 219–224.
Golovatch S.I., Palatov D.M., Turbanov I.S., Kniss V.A., Gazaryan S., Snit’ko V.P., Decu V., Juberthie C. & Nazareanu G. 2018. Subterranean biota of the European part of Russia: A review. Invertebrate Zoology 15 (2): 153–213. https://doi.org/10.15298/invertzool.15.2.01
Gurney R. 1933. British Fresh-water Copepoda. Volume III. The Ray Society, London. https://doi.org/10.5962/bhl.title.82138
Herbst H.V. 1987. Zwei neue Cyclopoiden (Crustacea, Copepoda) von der Insel Barbados. Bijdragen tot de Dierkunde 57 (1): 59–70. https://doi.org/10.1163/26660644-05701006
Hołyńska M. 2006. Phylogeny of Mesocyclops (Copepoda: Cyclopidae) inferred from morphological characters. Zoological Journal of the Linnean Society 147 (1): 1–70. https://doi.org/10.1111/j.1096-3642.2006.00231.x
Huys R. & Boxshall G.A. 1991. Copepod Evolution. The Ray Society, London.
Iepure S. & Defaye D. 2003. Redescription of Teratocyclops cubensis Pleşa, 1981 (Copepoda, Cyclopoida, Cyclopidae) from Cuba. Crustaceana 76 (5): 591–604. https://doi.org/10.1163/156854003322316227
Karaman S. 1935. Die Fauna der unterirdischen Gewässer Jugoslaviens: Mit 5 Abbildungen. Internationale Vereinigung für theoretische und angewandte Limnologie: Verhandlungen 7 (1): 46–73. https://doi.org/10.1080/03680770.1935.11902405
Karanovic T. 2000. On Reidcyclops, new genus (Crustacea, Copepoda), with the first description of the male of Reidcyclops trajani (Reid & Strayer, 1994), new combination. Beaufortia 50 (3): 79–88.
Karanovic T. 2001. Description of Allocyclops montenegrinus, spec. nov. and a revision of the genus Allocyclops Kiefer, 1932. Spixiana 24 (1): 19–27.
Karanovic T. 2003. First representative of the genus Allocyclops Kiefer, 1932 (Crustacea, Copepoda, Cyclopoida) from the Australian subterranean waters. Annales de Limnologie – International Journal of Limnology 39 (2): 141–149. https://doi.org/10.1051/limn/2003012
Karanovic T. 2004a. Subterranean Copepoda (Crustacea, Copepoda) from Arid Western Australia. Brill, Leiden. https://doi.org/10.1163/9789047412779
Karanovic T. 2004b. The genus Metacyclops Kiefer in Australia (Crustacea: Copepoda: Cyclopoida), with description of two new species. Records of the Western Australian Museum 22 (3): 193–212. https://doi.org/10.18195/issn.0312-3162.22(3).2004.193-212
Karanovic T. 2005. Two new genera and three new species of subterranean cyclopoids (Crustacea, Copepoda) from New Zealand, with redescription of Goniocyclops silvestris Harding, 1958. Contributions to Zoology 74 (3–4): 223–254. https://doi.org/10.1163/18759866-0740304002
Karanovic T. 2006. Subterranean copepods (Crustacea, Copepoda) from the Pilbara region in Western Australia. Records of the Western Australian Museum, Supplement 70 (1): 1–239. https://doi.org/10.18195/issn.0313-122x.70.2006.001-239
Karanovic T., Eberhard S.M. & Murdoch A. 2011. A cladistic analysis and taxonomic revision of Australian Metacyclops and Goniocyclops, with description of four new species and three new genera (Copepoda, Cyclopoida). Crustaceana 84 (1): 1–67. https://doi.org/10.1163/001121610X546698
Karanovic T., Yoo H. & Lee W. 2012. A new cyclopoid copepod from Korean subterranean waters reveals an interesting connection with the Central Asian fauna (Crustacea: Copepoda: Cyclopoida). Journal of Species Research 1 (2): 156–174. https://doi.org/10.12651/jsr.2012.1.2.156
Karaytuğ S., Bozkurt A. & Sönmez S. 2018. A new hyporheic Monchenkocyclops Karanovic, Yoo & Lee, 2012 (Crustacea: Copepoda) from Turkey with special emphasis on antennulary homology. Zoosystema 40 (1): 43–58. https://doi.org/10.5252/zoosystema2018v40a2
Kiefer F. 1955. Neue Cyclopoida Gnathostoma (Crustacea Copepoda) aus Madagaskar. II. Cyclopinae. Zoologischer Anzeiger 154 (9–10): 222–232.
Lee J.M. & Chang C.Y. 2012. Discovery of the rarely known genus Psammophilocyclops (Cyclopidae Cyclopinae) from a water purification plant in South Korea. Animal Cells and Systems 16 (3): 245–253. https://doi.org/10.1080/19768354.2011.637578
Lindberg K. 1954. Un cyclopide (Crustacé Copépode) troglobie de Madagascar. Avec remarques sur un groupe de cyclopides très évolués, cavernicoles et muscicoles. Hydrobiologia 6 (1–2): 97–119. https://doi.org/10.1007/bf00039414
Lowndes A.G. 1934. Reports of an expedition to Brazil and Paraguay in 1926-7 supported by the Trustees of the Percy Sladen Memorial Fund and the Executive Committee of the Carnegie Trust for Scotland. Journal of the Linnean Society of London, Zoology 39 (263): 83–131. https://doi.org/10.1111/j.1096-3642.1934.tb00260.x
Marin I.N. & Palatov D.M. 2021. Volgonyx gen. n. and Pontonyx gen. n., two new genera of the family Crangonyctidae (Crustacea: Amphipoda) from the southeastern Europe. Arthropoda Selecta 30 (1): 43–61. https://doi.org/10.15298/arthsel.30.1.05
Marin I.N. & Palatov D.M. 2024a. Distribution of the genus Volgonyx Marin et Palatov, 2021 (Crustacea: Amphipoda: Crangonyctidae) in groundwater habitats along the Lower Volga with a description of a new species. Arthropoda Selecta 33 (3): 342–354. https://doi.org/10.15298/arthsel.33.3.04
Marin I.N. & Palatov D.M. 2024b. A new species of the genus Uralocrangonyx Marin et Palatov, 2022 (Amphipoda: Crangonyctidae) from the Zhiguli Mountains, Samara region, Russia. Arthropoda Selecta 33 (1): 76–86. https://doi.org/10.15298/arthsel.33.1.07
Monchenko V.I. 1972. Tsiklopy (Copepoda, Cyclopoida) gruntovykh vod pustyni Kyzylkum. Trudy Zoologicheskogo Instituta Akademia Nauk SSSR 51: 78–97.
Monchenko V.I. 1974. Fauna of Ukraine. Cyclopidae. Naukova dumka, Kiev.
Monchenko V.I. 1983. Speocyclops cinctus sp. n. (Crustacea, Copepoda) s severnogo sklona Glavnogo khrebta Bol’shogo Kavkaza. Zoologicheskii Zhurnal 62 (5): 681–688.
Monchenko V.I. 1985. Novy vid roda Diacyclops (Crustacea, Copepoda) iz Zakavkaz’ya. Vestnik Zoologii 5: 19–25.
Monchenko V.I. 1986. Pervyy endemichnyy rod veslonogikh rakoobraznykh (Copepoda, Cyclopidae) iz Kaspiyskogo morya. Zoologicheskii Zhurnal 65 (3): 333–340.
Monchenko V.I. 2010. A new species of Speocyclops (Crustacea: Copepoda) from interstitial waters of the eastern Lesser Caucasus. Zoosystematica Rossica 19 (2): 179–187. https://doi.org/10.31610/zsr/2010.19.2.179
Monchenko V.I. & Von Vaupel Klein J.C. 1999. Oligomerization in Copepoda Cyclopoida as a kind of orthogenetic evolution in the animal kingdom. Crustaceana 72 (3): 241–264. https://doi.org/10.1163/156854099503320
Novikov A.A., Sharafutdinova D.N., Mayor T.Y. & Chertoprud E.S. 2024. A new species of Diacyclops (Copepoda, Cyclopoida) from the D. crassicaudis (Sars, 1863) species group with critical taxonomy remarks. Diversity 16 (4): 208. https://doi.org/10.3390/d16040208
Pesce G. 1996. Towards a revision of Cyclopinae copepods (Crustacea, Cyclopidae). Fragmenta entomologica 28 (2): 189–200.
Petkovski T.K. 1971. Einige neue und seltene subterrane Cyclopiden (Crustacea, Copepoda) aus Jugoslavien. Acta Musei Macedonici Scientiarum Naturalium, Skopje 12 (5): 77–114.
Reid J.W. 1988. Yansacyclops ferrarii, new genus, new species (Copepoda: Cyclopoida) from the Amazon Basin, Brazil. Hydrobiologia 167/168: 429–434. https://doi.org/10.1007/bf00026335
Reid J.W. 1993a. Fimbricyclops jimhensoni, new genus, new species (Copepoda: Cyclopoida: Cyclopidae), from bromeliads in Puerto Rico. Journal of Crustacean Biology 13 (2): 383–392. https://doi.org/10.1163/193724093x00156
Reid J.W. 1993b. Diacyclops virginianus, a new species of Cyclopoida (Crustacea: Copepoda) from Goose Creek, Virginia. Maryland Naturalist 37 (1–2): 36–45.
Reid J.W. & Spooner J.D. 1998. Stolonicyclops heggiensis, new genus, new species, from Georgia, USA (Copepoda: Cyclopoida: Cyclopidae). Journal of Crustacean Biology 18 (2): 405–411. https://doi.org/10.2307/1549333
Reid J.W. & Strayer D.L. 1994. Diacyclops dimorphus, a new species of copepod from Florida, with comments on morphology of interstitial cyclopine cyclopoids. Journal of the North American Benthological Society 13 (2): 250–265. https://doi.org/10.2307/1467243
Reid J.W., Strayer D.L., McArthur J.V., Stibbe S.E. & Lewis J.J. 1999. Rheocyclops, a new genus of copepods from the southeastern and central U.S.A. (Copepoda: Cyclopoida: Cyclopidae). Journal of Crustacean Biology 19 (2): 384–396.
Rocha C.E.F. & Bjornberg M.H.G.C. 1987. Copepods of the Juréia Ecological Reserve, State of Sao Paulo, Brazil. II. The genera Hesperocyclops, Muscocyclops, and Bryocyclops (Cyclopoida, Cyclopidae). Hydrobiologia 153: 97–107. https://doi.org/10.1007/BF00006642
Sabater F. & Vila P.B. 1992. The hyporheic zone considered as an ecotone. Homage to Ramon Margalef, or, Why There is Such Pleasure in Studying Nature: 35–43.
Sanoamuang L., Boonyanusith C. & Brancelj A. 2019. A new genus and new species of stygobitic copepod (Crustacea: Copepoda: Cyclopoida) from Thien Duong Cave in Central Vietnam, with a redescription of Bryocyclops anninae (Menzel, 1926). Raffles Bulletin of Zoology 67: 189–205. https://doi.org/10.26107/RBZ-2019-0016
Schutze M.L.M., da Rocha C.E.F. & Boxshall G.A. 2000. Antennulary development during the copepodid phase in the family Cyclopidae (Copepoda, Cyclopoida). Zoosystema 22 (4): 749–806.
Sewell R.B.S. 1949. The littoral and semi-parasitic Cyclopoida, Monstrilloida and Notodelphyoida. John Murray Expedition 1933–34 / Scientific Reports 9: 17–199.
Tang D. & Knott B. 2009. Freshwater cyclopoids and harpacticoids (Crustacea: Copepoda) from the Gnangara Mound region of Western Australia. Zootaxa 2029 (1): 1–70. https://doi.org/10.11646/zootaxa.2029.1.1
Tokinova R.P. & Berdnik S.V. 2021. An annotated checklist of freshwater crustaceans (Arthropoda) of Tatarstan. Russian Journal of Applied Ecology 1 (25): 21–35.
Totakura V.R. & Ranga Reddy Y. 2015. Groundwater cyclopoid copepods of peninsular India, with description of eight new species. Zootaxa 3945 (1): 1–93. https://doi.org/10.11646/zootaxa.3963.3.9
Turbanov I.S., Palatov D.M. & Golovatch S.I. 2016. The state of the art of biospeleology in Russia and other countries of the former Soviet Union: a review of the cave (endogean) invertebrate fauna. 1. Introduction—Crustacea. Entomological Review 96 (7): 926–963. https://doi.org/10.1134/s0013873816070162
Van de Velde I. 1984. Revision of the African species of the genus Mesocyclops Sars, 1914 (Copepoda: Cyclopidae). Hydrobiologia 109 (1): 3–66. https://doi.org/10.1007/bf00006297
Watiroyram S. 2021. A new representative of the genus Bryocyclops Kiefer, 1927 from a karst cave in north-eastern Thailand (Copepoda, Cyclopoida, Cyclopidae) and comments on the generic affinities. Zoosystematics and Evolution 97 (1): 97–109. https://doi.org/10.3897/zse.97.52354
Watiroyram S. & Koompoot K. 2024. Siamcyclops isanus sp. nov. (Copepoda, Cyclopoida, Cyclopidae), a new cave-dwelling species from northeastern Thailand. Subterranean Biology 49: 185–200. https://doi.org/10.3897/subtbiol.49.135303
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