New insights into the Enchytraeus albidus complex (Annelida, Enchytraeidae), with the description of three new species from seashores in Italy and Croatia


Between 2019 and 2021, samplings were carried out from seashores in Italy and Croatia, where specimens were found morphologically similar to the species of the Enchytraeus albidus complex. The taxon Enchytraeus albidus was recently divided into a number of separate species, and the new Italian and Croatian specimens of Enchytraeus proved to be three additional species, all new to science, based on the results of morphological and molecular studies. In this paper, we present the description of these new species, namely Enchytraeus adrianensis sp. nov., Enchytraeus andrasi sp. nov. and Enchytraeus andrasiformis sp. nov., and provide additional morphological data and new reference sequences for E. albidus s. str., E. krumbachi, E. irregularis and further unidentified specimens that belong to the E. albidus group collected formerly from Hungary, Korea, Svalbard and Kerguelen Islands.

Author Biography

Hajnalka Nagy

Department of Microbiology, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C,
H-1117 Budapest, Hungary


Arslan N., Timm T., Rojo V., Vizcaíno A. & Schmelz R.M. 2018. A new species of Enchytraeus (Enchytraeidae, Oligochaeta) from the profundal of Lake Van, the world’s largest soda lake (Turkey, East Anatolia). Zootaxa 4382 (2): 367–380.

Bely A.E. & Wray G.A. 2004. Molecular phylogeny of naidid worms (Annelida: Clitellata) based on cytochrome oxidase I. Molecular Phylogenetics and Evolution 30: 50–63.

Birkemoe T. & Dózsa-Farkas K. 1994. New records of Enchytraeidae (Oligochaeta) from Spitsbergen, Svalbard. Fauna Norvegica Series A 15: 35–44.

Bouckaert R., Heled J., Kühnert D., Vaughan T., Wu C-H., Xie D., Suchard M.A., Rambaut A. & Drummond A.J. 2014. BEAST 2: A Software Platform for Bayesian Evolutionary Analysis. PLoS Computational Biology 10: e1003537.

Čejka B. 1913. Litorea krumbachi n. spec. n. gen. Ein Beitrag zur Systematik der Enchytraeiden. Zoologischer Anzeiger 17: 145–151.

Christensen B. 1960. A comparative cytological investigation of the reproductive cycle of an amphimictic diploid and a parthenogenetic triploid form of Lumbricillus lineatus (O.F.M.) (Oligochaeta, Enchytraeidae). Chromosoma 11: 365–379.

Christensen B. 1961. Studies on cyto-taxonomy and reproduction in the Enchytraeidae with notes on parthenogenesis and polyploidy in the animal kingdom. Hereditas 47: 387–450.

Christensen B. & Glenner H. 2010. Molecular phylogeny of Enchytraeidae (Oligochaeta) indicates separate invasions of the terrestrial environment. Journal of Zoological Systematics and Evolutionary Research 48: 208–212.

Coates K. & Ellis D.V. 1981. Taxonomy and distribution of marine Enchytraeidae (Oligochaeta) in British Columbia. Canadian Journal of Zoology 59: 2129–2150.

Colgan D.J., McLauchlan A.A., Wilson G.D.F., Livingston S.P., Edgecombe G.D., Macaranas J., Cassis G. & Gray M.R. 1998. Histone H3 and U2 snRNA DNA sequences and arthropod molecular evolution. Australian Journal of Zoology 46: 419–437.

Collado R., Schmelz R., Moser T. & Römbke J. 1999. Enchytraeid Reproduction Test (ERT): Sublethal responses of two Enchytraeus species (Oligochaeta) to toxic chemicals. Pedobiologia 43: 625–629.

CorelDRAW Graphic Suite 2021. Available from [accessed 24 Apr. 2023].

Dózsa-Farkas K. 1995. Self-fertilisation: An adaptive strategy in widespread enchytraeids. European Journal of Soil Biology 31 (4): 207–215.

Dózsa-Farkas K., Felföldi T. & Hong Y. 2015. New enchytraeid species (Enchytraeidae, Oligochaeta) from Korea. Zootaxa 4006 (1): 171–197.

Dózsa-Farkas K. 2019. Enchytraeids of Hungary (Annelida: Clitellata: Enchytraeidae). Pedozoologica Hungarica 7. Eötvös University Press, Budapest.

d’Udekem J. 1855. Nouvelles classification des Annélides sétigères abranches. Bulletins de l’Académie royale des sciences, des lettres et des beaux-arts de Belgique 22 (2): 533–557.

Eisen G. 1904. Enchytraeidae of the west Coast of North America. Harriman Alaska Series. New York 12: 1–126.

Erséus C. & Gustafsson D. 2009. Cryptic speciation in clitellate model organisms. In: Annelids in Modern Biology. John Wiley & Sons, Hoboken.

Erséus C., Rota E., Matamoros L. & De Wit P. 2010. Molecular phylogeny of Enchytraeidae (Annelida, Clitellata). Molecular Phylogenetics and Evolution 57 (2): 849–858.

Erséus C., Klinth M.J., Rota E., Wit P.D., Gustafsson D.R. & Martinsson S. 2019. The popular model annelid Enchytraeus albidus is only one species in a complex of seashore white worms (Clitellata, Enchytraeidae). Organisms Diversity & Evolution 19: 105–133.

Folmer O., Black M., Hoeh W., Lutz R. & Vrijenhoek R. 1994. DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates. Molecular Marine Biology and Biotechnology 3: 294–299.

Heled J. & Drummond A.J. 2010. Bayesian inference of species trees from multilocus data. Molecular Biology and Evolution 27: 570–580.

Henle F.G.J. 1837. Ueber Enchytraeus, eine neue Anneliden-Gattung. Archiv für Anatomie, Physiologie und Wissenschaftliche Medicin 74–90.

Hong Y. & Dózsa-Farkas K. 2018. New description of enchytraeid species (Clitellata: Enchytraeidae) from Korea. Journal of Species Research 7: 80–91.

INKSCAPE 1.2.2 – Draw freely. Available from [accessed 24 Apr. 2023].

Kane R.A. & Rollinson D. 1994. Repetitive sequences in the ribosomal DNA internal transcribed spacer of Schistosoma haematobium, Schistosoma intercalatum and Schistosoma mattheii. Molecular and Biochemical Parasitology 63: 153–156.

Kasprzak K. 1984. The previous and contemporary conceptions on phylogeny and systematic classifications of Oligochaeta Annelida. Annales zoologici, Warszawa 38 (9): 205–223.

Kumar S., Stecher G. & Tamura K. 2016. MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets. Molecular Biology and Evolution 33: 1870–1874.

Martinsson S. & Erséus C. 2018. Cryptic diversity in supposedly species-poor genera of Enchytraeidae (Annelida: Clitellata). Zoological Journal of the Linnean Society 183: 749–762.

Matamoros L., Rota E. & Erséus C. 2012. Cryptic diversity among the achaetous Marionina (Annelida, Clitellata, Enchytraeidae). Systematics and Biodiversity 10 (4): 509–525.

Michaelsen W. 1885. Vorlaufige Mitteilungen über Archenchytraeus Möbii n. sp. Zoologischer Anzeiger 8: 237–239.

Michaelsen W. 1886. Untersuchungen über Enchytraeus Möbii Mich. und andere Enchytraeiden. Lipsius & Tischer, Kiel.

Michaelsen W. 1919. Über die Beziehungen der Hirudineen zu den Oligochäten. Mitteilungen aus dem Hamburgischen zoologischen Museum und Institut 36: 131–153.

Michaelsen W. 1926. Zur Kenntnis einheimischer und ausländischer Oligochäten. Zoologische Jahrbücher Abteilung für Systematik, Geographie und Biologie der Tiere 51: 255–328.

Nielsen C.O. & Christensen B. 1959. The Enchytraeidae. Critical revision and taxonomy of European species (studies on Enchytraeidae VII). Natura Jutlandica 8–9: 1–160.

Nielsen C.O. & Christensen B. 1961. The Enchytraeidae. Critical revision and taxonomy of European species. Supplement 1. Natura Jutlandica 10: 1–23.

O’Connor F.B. 1962. The extraction of Enchytraeidae from soil. In: Murphy P.W. (ed.) Progress in Soil Zoology: 279–285. Butterworths Publishers, London.

Rambaut A. 2018. FigTree version 1.4.4. Computer program and documentation distributed by the author. Available from [accessed 25 Apr 2023].

Rambaut A., Drummond A.J., Xie D., Baele G. & Suchard M.A. 2018. Posterior summarisation in Bayesian phylogenetics using Tracer 1.7. Systematic Biology syy032.

Rougerie R., Decaëns T., Deharveng L., Porco D., James S.W., Chang C.-H., Richard B., Potapov M., Suhardjono Y. & Hebert, P.D.N. 2009. DNA barcodes for soil animal taxonomy. Pesquisa Agropecuaria Brasileira 44: 789–802.

Römbke J. 1989. Enchytraeus albidus (Enchytraeidae, Oligochaeta) as a test organism in terrestrial laboratory systems. Archives of Toxicology, Suppl. 13: 402–405.

Schmelz R.M. & Collado R. 2010. A guide to European terrestrial and freshwater species of Enchytraeidae (Oligochaeta). Soil Organisms 82: 1–176.

Schmelz R.M. & Collado R. 2012. An updated checklist of currently accepted species of Enchytraeidae (Oligochaeta, Annelida). Newsletter on Enchytraeidae 12: 67–87.

Sjölin E., Erséus C. & Källersjo M. 2005. Phylogeny of Tubificidae (Annelida, Clitellata) based on mitochondrial and nuclear sequence data. Molecular Phylogenetics and Evolution 35: 431–441.

von Bülow T. 1957. Systematisch-autökologische Studien an eulitoralen Oligochaeten der Kimbrischen Halbinsel. Kieler Meeresforschungen 13: 96–116.

White T.J., Bruns T., Lee S. & Taylor J. 1990. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis M.A., Gelfand D.H., Sninsky J.J. & White T.J. (eds) PCR Protocols: A Guide to Methods and Applications: 315–322. Academy Press, San Diego.

How to Cite
Nagy, H., Dózsa-Farkas, K., & Felföldi, T. (2023). New insights into the Enchytraeus albidus complex (Annelida, Enchytraeidae), with the description of three new species from seashores in Italy and Croatia. European Journal of Taxonomy, 870(1), 107–145.
Research article