Microstomum (Platyhelminthes, Macrostomorpha, Microstomidae) from the Swedish west coast: two new species and a population description

  • Sarah Atherton Naturhistoriska riksmuseet, Box 50007, 104 05, Stockholm
  • Ulf Jondelius Naturhistoriska riksmuseet, Box 50007, 104 05, Stockholm
Keywords: Macrostomorpha, Macrostomida, flatworm, meiofauna, turbellaria


Two new species of marine Platyhelminthes, Microstomum laurae sp. nov. and Microstomum edmondi sp. nov. (Macrostomida: Microstomidae) are described from the west coast of Sweden. Microstomum laurae sp. nov. is distinguished by the following combination of characters: rounded anterior and posterior ends; presence of approximately 20 adhesive papillae on the posterior rim; paired lateral red eyespots located level with the brain; preoral gut extending anterior to brain and very small sensory pits. Microstomum edmondi sp. nov. is a protandrous hermaphrodite with a single ovary, single testis and male copulatory organ with stylet. It is characterized by a conical pointed anterior end, a blunt posterior end with numerous adhesive papillae along the rim, and large ciliary pits. The stylet is shaped as a narrow funnel with a short, arched tip. In addition, the first records of fully mature specimens of Microstomum rubromaculatum von Graff, 1882 from Fiskebäckskil and a phylogenetic analysis of Microstomum Schmidt, 1848 based on the mitochondrial cytochrome oxidase I (COI) gene are presented.


Adami M., Damborenea C. & Ronderos J. 2012. A new limnic species of Macrostomum (Platyhelminthes: Macrostomida) from Argentina and its muscle arrangement labeled with phalloidin. Zoologischer Anzeiger 251: 197–205. https://doi.org/10.1016/j.jcz.2011.08.006

Akaike H. 1974. A new look at the statistical model identification. IEEE Transactions on Automatic Control 19: 716–723. https://doi.org/10.1109/TAC.1974.1100705

Armonies W. 1988. Common pattern of Platyhelminthes distribution in North Sea salt marshes and in the Baltic Sea. Archiv für Hydrobiologie 111: 625–636.

Ax P. 1956. Les Turbellariés des étangs côtiers du littoral méditerranéen de la France méridionale. Vie et Milieu supplément 5: 1–152.

Bauchhenss J. 1971. Die kleinturbellarien Frankens. Ein Beitrag zur Systematik und Ökologie der Turbellarien excl. Tricladida in Süddeutschland. International Revue der Gesamten Hydrobiologia 56: 609–666.

Boyer T. & Levitus S. 1994. Quality control and processing of historical oceanographic temperature, salinity, and oxygen data. National Oceanic and Atmospheric Administration, National Environmental Satellite, Data, and Information Service 81: 1–72. US Department of Commerce, Washington DC.

Darriba D., Taboada G., Doallo R. & Posada D. 2012. jModelTest 2: more models, new heuristics and parallel computing. Nature Methods 9: 772–772. https://doi.org/10.1038/nmeth.2109

Fang C., Wang L., Zang Y. & Wang A. 2016. Two new species of brackish-water Macrostomum (Platyhelminthes, Macrostomida) from southern China. Zootaxa 4170 (2): 298–310. https://doi.org/10.11646/zootaxa.4170.2.4

Faubel A. 1974. Macrostomida (Turbellaria) von einem Sandstrand der Nordseeinsel Sylt. Mikrofauna Meeresboden 45: 339–370.

Faubel A. 1976. Populationsdynamik und Lebenszyklen interstitieller Acoela und Macrostomida (Turbellaria). Mikrofauna Meeresboden 56: 253–359.

Heitkamp U. 1982. Untersuchungen zur Biologie, Ökologie und Systematik limnischer Turbellarien periodischer und perennierender Kleingewässer Südniedersachsens. Archiv für Hydrobiologie supplement 64: 65–188.

Hellwig M. 1987. Ökologie freilebender Plathelminthen im Grenzraum Watt-Salzwiese lenitischer Gezeitenküsten. Microfauna Marina 3: 157–248.

Janssen T., Vizoso D., Schulte G., Littlewood D., Waeschenbach A. & Schärer L. 2015. The first multi-gene phylogeny of the Macrostomorpha sheds light on the evolution of sexual and asexual reproduction in basal Platyhelminthes. Molecular Phylogenetics and Evolution 92: 82–107. https://doi.org/10.1016/j.ympev.2015.06.004

Karling T. 1934. Ein Beitrag zur Kenntnis der Nemertinen des finnischen Meerbusens. Memoranda Societatis pro Fauna et Flora Fennica 10: 76–90.

Karling T. 1966. On nematocysts and similar structure in turbellarians. Acta Zoologica Fennica 116: 3–28.

Karling T. 1974. Turbellarian fauna of the Baltic proper: identification, ecology and biogeography. Fauna Fennica 27: 1–101.

Kolasa J., Strayer J. & Bannon-O’Donnell E. 1987. Microturbellarians from interstitial waters, streams, and springs in southeastern New York. Journal of the North American Benthological Society 6: 125–132. https://doi.org/10.2307/1467222

Luo H., Zhao P. & Wang A. 2011. Research on taxonomic characters and one new recorded species of genus Macrostomum (Platyhelminthes, Macrostomida) from China. Sichuan Journal of Zoology 30: 39–44. [In Chinese.]

Maddison W. 1997. Gene trees in species trees. Systematic Biology 46: 523–536. https://doi.org/10.1093/sysbio/46.3.523

Marcus E. 1950. Turbellaria Brasileiros. Boletins da Facultade de Filosofia Ciências e Letras Zoologia 17: 5–191.

Martens P. 1984. Comparison of three different extraction methods for Turbellaria. Marine Ecology Progress Series 14: 229–234. https://doi.org/10.3354/meps014229

Meixner J. 1938. Turbellaria (Strudelwürmer) I. Allgemeiner Teil. Die Tierwelt der Nord- und Ostsee. Akademischer Verlag, Leipzig.

Rieger R. 2001. Phylogenetic systematics of the Macrostomorpha. In: Littlewood D. & Bray R. (eds) Interrelationships of the Platyhelminthes: 28–38. Taylor & Francis Inc., New York.

Rieger R., Tyler S., Smith J. & Rieger G. 1991. Platyhelminthes: Turbellaria. In: Harrison F. & Bogish B. (eds). Microscopic Anatomy of Invertebrates. Vol. 3: Platyhelminthes and Nemertinea: 7–140. Wiley-Liss. Inc., New York.

Rogozin A. 2015. New species of Turbellaria in the fauna of the Urals. Biology Bulletin 42: 755–758. https://doi.org/10.1134/S1062359015080075

Schockaert E. 2014. Marine Macrostomorpha (Platyhelminthes, Rhabditophora) from the Algarve (Southern Portugal). Zootaxa 3872: 577–590. https://doi.org/10.11646/zootaxa.3872.5.8

Silvestro I. & Michalak D. 2012. raxmlGUI: a graphical front-end for RAxML. Organism Diversity and Evolution 12: 335–337. https://doi.org/10.1007/s13127-011-0056-0

Southern R. 1936. Turbellaria of Ireland. Proceedings of the Royal Irish Academy section B 43: 43–72.

Steinböck O. 1931. Marine Turbellaria. In: Jensen S., Lundebeck W. & Mortensen T. (eds) Zoology of the Faeroes. A.F. Høst & Søn, Copenhagen.

Steinböck O. 1938. Marine Turbellaria. The Zoology of Iceland 2 (9): 1–26.

Sun T., Zhang L., Wang A. & Zhang Y. 2014. Three new species of freshwater Macrostomum (Platyhelminthes, Macrostomida) from southern China. Zootaxa 4012: 120–134. https://doi.org/10.11646/zootaxa.4012.1.6

Tamura K. & Nei M. 1993. Estimation of the number of nucleotide substitutions in the control region of mitochondrial DNA in humans and chimpanzees. Molecular Biology and Evolution 10: 512–526.

Tamura K., Peterson D., Peterson N., Stecher G., Nei M. & Kumar S. 2011. MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Molecular Biology and Evolution 28: 2731–2739. https://doi.org/10.1093/molbev/msr121

Telford M., Herniou E., Russell R. & Littlewood D. 2000. Changes in mitochondrial genetic codes as phylogenetic characters: two examples from the flatworms. Proceedings of the National Academy of Sciences 97: 11359–11364. https://doi.org/10.1073/pnas.97.21.11359

Von Graff L. 1882. Monographie der Turbellarien: I. Rhabdocoelida. Verlag Wilhelm Engelmann, Leipzig.

Von Graff L. 1913. Turbellaria II. Rhabdocoelida. Das Tierreich, eine Zusammenstellung und Kennzeichnung der rezenten Tierformen 35, Verlag Friedländer und Sohn, Berlin.

Westblad E. 1953. Marine Macrostomida (Turbellaria) from Scandinavia and England. Arkiv för Zoologi 4: 391–408.

How to Cite
Atherton, S., & Jondelius, U. (2018). Microstomum (Platyhelminthes, Macrostomorpha, Microstomidae) from the Swedish west coast: two new species and a population description. European Journal of Taxonomy, (398). https://doi.org/10.5852/ejt.2018.398