Enchytraeus demutatus sp. nov. (Enchytraeidae, Oligochaeta) has characters hitherto unrecorded in the genus


  • Rüdiger M. Schmelz IfAB Institute of Applied Soil Biology, Tomberg 24a, 22337 Hamburg, Germany; University of A Coruña, Science Faculty, GIBE, Evolutionary Biology Group, CICA, Centro de Investigaciones Científicas Avanzadas, As Carballeiras s/n, Campus de Elviña, 15071 A Coruña, Spain
  • Mårten J. Klinth Department of Biological & Environmental Sciences, University of Gothenburg, P.O. Box 463, SE-405 30 Gothenburg, Sweden
  • Christina Chalkia Agricultural University of Athens, School of Plant Sciences, Faculty of Crop Science, Laboratory of Agricultural Zoology and Entomology, 75 Iera Odos, 11855 Athens, Greece
  • Pelagia Anastasiadou Benaki Phytopathological Institue, 8 Stefanou Delta str., 14561 Kifissa, Greece
  • Evangelia Vavoulidou Soil Science Institute of Athens, 1 S. Venizelou str, 14123 Likovrisi, Attikis




Clitellata, soil fauna, soil biodiversity, taxonomy


A new species of enchytraeids with peculiar characters is described, Enchytraeus demutatus sp. nov. The species differs from all known species of Enchytraeus in features of the oesophageal appendages and the male efferent apparati. The oesophageal appendages insert ventro-laterally below the pharyngeal pad and not dorsally behind the pad, as is usual in the genus; furthermore, their histology is different. The male efferent apparati have each an unusually wide and short vas deferens, and accessory glands are attached to the inner surface of the male glandular bulb, in close vicinity to the male pore. The remaining characters agree with the genus diagnosis of Enchytraeus, notably the presence of testis sacs and oesophageal appendages. The bisetose worms are about 5 mm long and 0.2–0.3 mm wide. The peculiarities of the oesophageal appendages raised the possibility to place the species in a new genus. DNA sequencing was performed to provide molecular identifiers and to assess the generic placement of the species. The molecular phylogenetic analysis, based on a concatenation of the six genetic markers 12S, 16S, 18S, 28S, COI and H3 placed E. demutatus inside the well-supported (PP  =  0.99) Enchytraeus clade and not outside, hence the new species is to be considered a member of Enchytraeus. The tree includes species that cover a wide range of the morphological diversity in Enchytraeus; here E. demutatus sp. nov. groups with a sub-branch that includes the other bisetose species, also the fragmenting ones, but also one species with 3 chaetae per bundle; whereas species of the E. buchholzi-group and the E. albidus-group, respectively, form clades of their own. E. demutatus sp. nov. was found in soil samples derived from a tomato field of a private greenhouse farm in the regional division of Ilia, West Greece, together with abundant E. bigeminus.


Baylis, H. A. (1915): A parasitic oligochaete, and other inhabitants of the gill-chambers of landcrabs. – The Annals and Magazine of Natural History, including Zoology, Botany and Geology, London, series 8, vol. 15: 378–383.

Bouguenec, V. & N. Giani (1987): Deux nouvelles espèces d’Enchytraeus (Oligochaeta, Enchytraeidae) et redescription d’E. bigeminus Niel. & Chr. Remarques sur le genre Enchytraeus. – Annales de Limnologie, Toulouse 23: 9–22.

Chen, J., Z. C. Xie & S. P. He (2006): A taxonomic study of Oconnorella (Enchytraeidae, Oligochaeta) from Changbaishan Mountain, China. – Zoological Science 23: 917–922 [https://doi.org/10.2108/zsj.23.000].

Collado, R., E. Haß-Cordes & R. M. Schmelz (2012): Microtaxonomy of fragmenting Enchytraeus species using molecular markers, with a comment on species complexes in enchytraeids. – Turkish Journal of Zoology 36: 85–94 [https://doi.org/10.3906/zoo-1002-70].

Dózsa-Farkas, K. & T. Felföldi (2015): Unexpected occurrence of Hemifridericia bivesiculata Christensen & Dozsa–Farkas, 2006 in Hungary, a species presumed to be endemic to Devon Island, Canada, and its comparative analysis with H. parva Nielsen & Christensen, 1959 (Enchytraeidae, Oligochaeta). – Zootaxa 3914: 185–194 [https://doi.org/10.11646/zootaxa.3914.2.8].

Erseus, C., M. J. Klinth, E. Rota, P. De Wit, D. R. Gustafsson & S. Martinsson (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 [https://doi.org/10.1007/s13127-019-00402-6].

Erséus, C., E. Rota, L. Matamoros & P. De Wit (2010): Molecular phylogeny of Enchytraeidae (Annelida, Clitellata). – Molecular Phylogenetics and Evolution 57: 849–858 [https://doi.org/10.1016/j.ympev.2010.07.005].

Friend, H. (1899): New British annelids. – The Zoologist Series, 4(3): 262–265.

Hrabě, S. (1935): Oligochety ozera Issyk-Kul. Die Oligochaeten des Issykkulsees. –Akademiya Nauk SSSR, Trudy Kirgizskoj kompleksnoj expedicii 3: 73–85.

Katoh, K., K. Misawa, K. I. Kuma & T. Miyata (2002) MAFFT: a novel method for rapid multiple sequence alignment based on fast Fourier transform. – Nucleic Acids Research 30: 3059–3066 [https://doi.org/10.1093/nar/gkf436].

Kearse, M., R. Moir, A.Wilson, S. Stones-Havas, M. Cheung, S. Sturrock, S. Buxton, A. Cooper, S. Markowitz, C. Duran, T. Thierer, B. Ashton, P.Mentjies, & A. Drummond (2012): Geneious Basic: an integrated and extendable desktop software platform for the organization and analysis of sequence data. – Bioinformatics 28(12): 1647–1649 [https://doi.org/10.1093/bioinformatics/bts199].

Martinsson, S., K. Dózsa-Farkas, E. Rota & C. Erséus (2017): Placing the forgotten: on the positions of Euenchytraeus and Chamaedrilus in an updated enchytraeid phylogeny (Clitellata: Enchytraeidae). – Invertebrate Systematics 31: 85–90 [https://doi.org/10.1071/IS16042].

Nakamura, Y. (1993): A new fragmenting enchytraeid species, Enchytraeus japonensis from a cropped Kuroboku soil in Fukushima, Northern Japan (Enchytraeids in Japan 5). – Edaphologia 50: 37–39.

Nielsen, C. O. & B. Christensen (1963): The Enchytraeidae. Critical revision and taxonomy of European species. Supplement 2. – Natura Jutlandica 10: 1–19.

Rambaut A., A. J. Drummond, D. Xie, G. Baele & M. A. Suchard (2018): Posterior summarisation in Bayesian phylogenetics using Tracer 1.7. – Systematic Biology 67: 901–904 [https://doi.org/10.1093/sysbio/syy032].

Rodriguez, P. & N. Giani (1986): Description de trois espèces nouvelles d‘Oligochètes aquatiques du Pays Basque (Espagne). – Hydrobiologia 139: 269–276.

Ronquist, F., M. Teslenko, P. van der Mark, D. L. Ayres, A. Darling, S. Höhna & J. P. Huelsenbeck (2012): MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. – Systematic Biology 61: 539–554 [https://doi.org/10.1093/sysbio/sys029].

Rota, E. & B. Healy (1994): The enchytraeid fauna of North Africa. – Hydrobiologia 278: 53–66.

Schmelz, R. M. & R. Collado (1999): Enchytraeus luxuriosus sp. nov., a new terrestrial oligochaete species (Enchytraeidae, Clitellata, Annelida). – Carolinea (Karlsruhe) 57: 93–100.

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

Schmelz, R. M., R. Collado & M. Myohara (2000): A taxonomical study of Enchytraeus japonensis (Enchytraeidae, Oligochaeta): Morphological and biochemical comparisons with E. bigeminus. – Zoological Science 17: 505–516 [https://doi.org/10.2108/0289-0003(2000)17[505:ATSOEJ]2.0.CO;2].

Stephenson, J. (1912): On a new species of Branchiodrilus and certain other aquatic Oligochaeta, with remarks on cephalization in the Naididae. – Records of the Indian Museum of Calcutta 7: 219–249.

Stephenson, J. (1914): On a collection of Oligochaeta mainly from Northern India. – Records of the Indian Museum of Calcutta 10: 321–366.

Wang, H., Z. C. Xie & Y. L. Liang (1999): Records of Enchytraeidae (Clitellata) from the People’s Republic of China. – Hydrobiologia 406: 57–66 [https://doi.org/


Westheide, W. & U. Graefe (1992): Two new terrestrial Enchytraeus species (Oligochaeta, Annelida). – Journal of Natural History 26: 479–488 [https://doi.org/10.1080/00222939200770311].

Xie, Z. & E. Rota (2001): Four new terrestrial species of Marionina (Clitellata, Enchytraeidae) from China and re-examination of M. hoffbaueri Möller. – Journal of Natural History 35: 1417–1431 [https://doi.org/10.1080/002229301317067610].




How to Cite

Schmelz, R. M. ., Klinth, M. J. ., Chalkia, C. ., Anastasiadou, P. ., & Vavoulidou, E. . (2019). Enchytraeus demutatus sp. nov. (Enchytraeidae, Oligochaeta) has characters hitherto unrecorded in the genus. SOIL ORGANISMS, 91(3), 87–96. https://doi.org/10.25674/so91iss3pp87