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Issue: Vol. 5722 No. 2: 19 Nov. 2025
Type: Article
Published: 2025-11-19
DOI: 10.11646/zootaxa.5722.2.6
Page range: 265-277
Abstract views: 51
PDF downloaded: 11

Description of a new bathyal species of Notocomplana (Platyhelminthes, Polycladida) collected from Bathymodiolus aggregations in a deep-sea hydrocarbon seep

College of Arts and Sciences; J. F. Oberlin University; Machida; Tokyo 194-0294; Japan
Research Institute for Global Change (RIGC); Japan Agency for Marine-Earth Science and Technology (JAMSTEC); Yokosuka; Kanagawa 237-0061; Japan
Sugashima Marine Biological Laboratory; Graduate School of Science; Nagoya University; Sugashima; Toba; Mie 517-0004; Japan; Centre for Marine & Coastal Studies; Universiti Sains Malaysia 11800 USM; Gelugor; Penang; Malaysia
Research Institute for Global Change (RIGC); Japan Agency for Marine-Earth Science and Technology (JAMSTEC); Yokosuka; Kanagawa 237-0061; Japan
Research Institute for Global Change (RIGC); Japan Agency for Marine-Earth Science and Technology (JAMSTEC); Yokosuka; Kanagawa 237-0061; Japan
Platyhelminthes Acotylea chemosynthesis-based ecosystem Leptoplanoidea systematics turbellarian

Abstract

Polyclad flatworms are free-living platyhelminths that inhabit various marine environments; however, their biodiversity in the deep sea remains poorly understood. Herein, we describe a new species of Notocomplana Faubel, 1983, Notocomplana profunda sp. nov., based on specimens collected from Bathymodiolus mussel aggregations in a deep-sea hydrocarbon seep off Hatsushima, Japan. This is the first report of a bathyal species of Notocomplana, which is dominated by shallow-water species. The new species is characterized by the absence of tentacles, eyespots, and any color pattern on the dorsal surface of the body and the presence of a seminal vesicle larger than a prostatic vesicle and a long, tubular Lang’s vesicle. A molecular phylogenetic analysis based on the partial sequences of two mitochondrial and two nuclear genes suggested that the strategy of N. profunda sp. nov. to use mussel aggregations was acquired by its shallow coastal ancestors.

 

References

  1. 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
  2. Bock, S. (1913) Studien über Polycladen. Zoologiska Bidrag från Uppsala, 2, 31–344.
  3. Boone, E.S. (1929) Five new polyclads from the California coast. Journal of Natural History, 3, 33–46. https://doi.org/10.1080/00222932908672934
  4. Brusa, F. & Damborenea, M.C. (2011) Polycladida Acotylea from Patagonia. Redescription of Crassiplana albatrossi (Pseudostylochidae), lectotype designation and first record of Notocomplana palta (Notoplanidae). Zootaxa, 2903 (1), 29–38. https://doi.org/10.11646/zootaxa.2903.1.3
  5. Castresana, J. (2000) Selection of conserved blocks from multiple alignments for their use in phylogenetic analysis. Molecular Biology and Evolution, 17, 540–552. https://doi.org/10.1093/oxfordjournals.molbev.a026334
  6. Chen, C., Methou, P., Yamamoto, D., Kayamori, M. & Nomaki, H. (2024) There and there again: Hydrothermal vent communities at Mokuyo Seamount, 30 years apart. Ecological Research, 40 (4), 389–402. https://doi.org/10.1111/1440-1703.12528
  7. Faubel, A. (1983) The Polycladida, Turbellaria. Proposal and establishment of a new system. Part I. The Acotylea. Mitteilungen des hamburgischen zoologischen Museums und Instituts, 80, 17–121.
  8. Freeman, D. (1933) The polyclads of the San Juan region of Puget Sound. Transactions of the American Microscopical Society, 52 (2), 107–146. https://doi.org/10.2307/3222188
  9. Gibson, R. (1994) Nemerteans. Field Studies Council, Shrewsbury, vii + 224 pp.
  10. Heath, H. & McGregor, E.A. (1912) New polyclads from Monterrey Bay, California. Proceeding of the Academy of Natural Sciences of Philadelphia, 64, 455–488.
  11. Hookabe, N., Jimi, N., Furushima, Y. & Fujiwara, Y. (2024) Discovery of deep-sea acoels from a chemosynthesis-based ecosystem. Biology Letters, 20 (7), 20230573. https://doi.org/10.1098/rsbl.2023.0573
  12. Hyman, L.H. (1939) Some polyclads of the New England coast, especially of the Woods Hole Region. Biological Bulletin, 76 (2), 127–152. https://doi.org/10.2307/1537854
  13. Hyman, L.H. (1953) The polyclad flatworms of the Pacific coast of North America. Bulletin of the American Museum of Natural History, 100, 269–392.
  14. Kato, K. (1938) On a pelagic polyclad, Planocera pellucida (Mertens) from Japan. Zoological Magazine, 50, 23l–233.
  15. Katoh, K. & Standley, D.M. (2013) MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Molecular Biology and Evolution, 30, 772–780. https://doi.org/10.1093/molbev/mst010
  16. Khalaman, V.V., Komendantov, A.Y., Golubovskaya, N.S. & Manoylina, P.A. (2021) Comparative efficiency of Mytilus edulis as engineering species for shallow-water fouling communities on artificial structures in the White Sea. Journal of the Marine Biological Association of the United Kingdom, 101 (3), 511–525. https://doi.org/10.1017/S0025315421000424
  17. Koopowitz, H., Silver, D. & Rose, G. (1976) Primitive nervous systems. Control and recovery of feeding behavior in the polyclad flatworm, Notoplana acticola. Biological Bulletin, 150 (3), 411–425. https://doi.org/10.2307/1540682
  18. Kozlov, A.M., Darriba, D., Flouri, T., Morel, B. & Stamatakis, A. (2019) RAxML-NG: a fast, scalable and user-friendly tool for maximum likelihood phylogenetic inference. Bioinformatics, 35 (21), 4453–4455. https://doi.org/10.1093/bioinformatics/btz305
  19. Kumar, S., Stecher, G. & Tamura, K. (2016) MEGA7: molecular evolutionary genetics analysis version 7.0 for bigger datasets. Molecular Biology and Evolution, 33 (7), 1870–1874. https://doi.org/10.1093/molbev/msw054
  20. Lanfear, R., Calcott, B., Ho, S.Y. & Guindon, S. (2012) PartitionFinder: combined selection of partitioning schemes and substitution models for phylogenetic analyses. Molecular Biology and Evolution, 29 (6), 1695–1701. https://doi.org/10.1093/molbev/mss020
  21. Lanfear, R., Frandsen, P.B., Wright, A.M., Senfeld, T. & Calcott, B. (2016) PartitionFinder 2: new methods for selecting partitioned models of evolution for molecular and morphological phylogenetic analyses. Molecular Biology and Evolution, 34 (3), 772–773. https://doi.org/10.1093/molbev/msw260
  22. Li, Y.X., Sun, Y., Lin, Y.T., Xu, T., Ip, J.C.H. & Qiu, J.W. (2023) Cold seep macrofauna. In: Chen, D. & Feng, D. (Eds.), South China Sea Seeps. Springer Singapore, Singapore, pp. 69–88. https://doi.org/10.1007/978-981-99-1494-4_5
  23. Litvaitis, M.K., Bolaños, D.M. & Quiroga, S.Y. (2019) Systematic congruence in Polycladida (Platyhelminthes, Rhabditophora): are DNA and morphology telling the same story? Zoological Journal of the Linnean Society, 186 (4), 865–891. https://doi.org/10.1093/zoolinnean/zlz007
  24. López-Márquez, V., Puente, A., Miller, J.P., Gutierrez, A. & Noreña, C. (2025) Exploring the intricate web of biodiversity: Notocomplana (Rhabditophora: Polycladida: Notocomplanidae) species networks in the North Pacific Ocean. Zoological Science, 42 (3), 287–298. https://doi.org/10.2108/zs240053
  25. Maghsoudlou, A. & Rahimian, H. (2013) Description of two new Discocelis species (Polycladida: Acotylea: Discocelidae) from the Persian Gulf with a review of the genus. Zootaxa, 3683 (3), 247–266. https://doi.org/10.11646/zootaxa.3683.3.2
  26. Marcus, E. (1954) Reports of the Lund University Chile Expedition 1948–49. II. Turbellaria. Lunds Universitets Arsskrift, 49, 3–115.
  27. Marquina, D., Fernández-Álvarez, F.Á. & Noreña, C. (2015) Five new records and one new species of Polycladida (Platyhelminthes) for the Cantabrian coast (North Atlantic) of the Iberian Peninsula. Journal of the Marine Biological Association of the United Kingdom, 95 (2), 311–322. https://doi.org/10.1017/S0025315414001106
  28. Newman, L.J. & Cannon, L.R.G. (1997) A new semi-terrestrial acotylean flatworm, Myoramixa pardalota gen. et sp. nov. (Platyhelminthes, Polycladida) from southeast Queensland. Memoirs of the Queensland Museum, 42, 311–314.
  29. Oya, Y. & Kajihara, H. (2017) Description of a new Notocomplana species (Platyhelminthes: Acotylea), new combination and new records of Polycladida from the northeastern Sea of Japan, with a comparison of two different barcoding markers. Zootaxa, 4282 (3), 526–542. https://doi.org/10.11646/zootaxa.4282.3.6
  30. Oya, Y. & Kajihara, H. (2019) A new bathyal species of Cestoplana (Polycladida: Cotylea) from the West Pacific Ocean. Marine Biodiversity, 49 (2), 905–911. https://doi.org/10.1007/s12526-018-0875-8
  31. Oya, Y. & Kajihara, H. (2020) Molecular phylogenetic analysis of Acotylea (Platyhelminthes: Polycladida). Zoological Science, 37 (3), 271–279. https://doi.org/10.2108/zs190136
  32. Oya, Y., Tsuyuki, A. & Kajihara, H. (2021) Description of a new species of Alloioplana (Polycladida: Stylochoplanidae) with an inference on its phylogenetic position in Leptoplanoidea. Proceedings of the Biological Society of Washington, 134 (1), 306–317. https://doi.org/10.2988/0006-324X-134.1.306
  33. Oya, Y., Nakajima, H. & Kajihara, H. (2022a) A new symbiotic relationship between a polyclad flatworm and a mantis shrimp: description of a new species of Emprosthopharynx (Polycladida: Acotylea) associated with Lysiosquilla maculata (Crustacea: Stomatopoda). Marine Biodiversity, 52 (5), 46. https://doi.org/10.1007/s12526-022-01288-y
  34. Oya, Y., Tsuyuki, A. & Kajihara, H. (2022b) Descriptions of two new species of Armatoplana (Polycladida: Stylochoplanidae) from the coasts of Japan, with their phylogenetic positions in Leptoplanoidea. Zootaxa, 5178 (5), 433–452. https://doi.org/10.11646/zootaxa.5178.5.2
  35. Oya, Y., Moritaki, T. & Tsuyuki, A. (2024a) Description of a new species of Pericelis (Polycladida, Diposthidae) from sunken wood in the bathyal zone in Japan. Journal of the Marine Biological Association of the United Kingdom, 104, e12. https://doi.org/10.1017/S0025315424000092
  36. Oya, Y., Maeno, A., Tsuyuki, A., Kohtsuka, H. & Kajihara, H. (2024b) Microfocus X-Ray computed tomography of Paraplanocera oligoglena (Platyhelminthes: Polycladida) with an evaluation of histological sections after scanning. Zoological Science, 41 (5), 471–478. https://doi.org/10.2108/zs240015
  37. Page, H.M. & Hubbard, D.M. (1987) Temporal and spatial patterns of growth in mussels Mytilus edulis on an offshore platform: relationships to water temperature and food availability. Journal of Experimental Marine Biology and Ecology, 111 (2), 159–179. https://doi.org/10.1016/0022-0981(87)90053-0
  38. Palumbi, S., Martin, A., Romano, S., McMillan, W.O., Stice, L. & Grabowski, G. (1991) The Simple Fools Guide to PCR, Ver. 2. Department of Zoology and Kewalo Marine Laboratory. University of Hawaii, Honolulu, 45 pp.
  39. Prudhoe, S. (1985) A Monograph on Polyclad Turbellaria. Oxford University Press, Oxford, 259 pp.
  40. Quiroga, S.Y., Bolaños, D.M. & Litvaitis, M.K. (2006) First description of deep-sea polyclad flatworms from the North Pacific: Anocellidus n. gen. profundus n. sp. (Anocellidae, n. fam.) and Oligocladus voightae n. sp. (Euryleptidae). Zootaxa, 1317 (1), 1–19. https://doi.org/10.11646/zootaxa.1317.1.1
  41. Quiroga, S.Y., Bolaños, D.M. & Litvaitis, M.K. (2008) Two new species of flatworms (Platyhelminthes: Polycladida) from the continental slope of the Gulf of Mexico. Journal of the Marine Biological Association of the United Kingdom, 88, 1363–1370. https://doi.org/10.1017/S0025315408002105
  42. Rodríguez, J., Hutchings, P.A. & Williamson, J.E. (2021) Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia. Zootaxa, 5024 (1), 1–63. https://doi.org/10.11646/zootaxa.5024.1.1
  43. Ronquist, F. & Huelsenbeck, J.P. (2003) MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics, 19 (12), 1572–1574. https://doi.org/10.1093/bioinformatics/btg180
  44. Schindelin, J., Arganda-Carreras, I., Frise, E., Kaynig, V., Longair, M., Pietzsch, T., Preibisch, S., Rueden, C., Saalfeld, S., Schmid, B., Tinevez, J.-Y, White, D.J., Hartenstein, V., Eliceiri, K., Tomancak, P. & Cardona, A. (2012) Fiji: an open-source platform for biological-image analysis. Nature Methods, 9 (7), 676–682. https://doi.org/10.1038/nmeth.2019
  45. Silva, A.P., Colaco, A., Ravara, A., Jakobsen, J., Jakobsen, K. & Cuvelier, D. (2021) The first whale fall on the Mid-Atlantic Ridge: Monitoring a year of succession. Deep Sea Research Part I: Oceanographic Research Papers, 178, 103662. https://doi.org/10.1016/j.dsr.2021.103662
  46. Sonnenberg, R., Nolte, A.W. & Tautz, D. (2007) An evaluation of LSU rDNA D1–D2 sequences for their use in species identification. Frontiers in Zoology, 4 (1), 1–12. https://doi.org/10.1186/1742-9994-4-6
  47. Thévenaz, P., Ruttimann, U.E. & Unser, M. (1998) A pyramid approach to subpixel registration based on intensity. IEEE Transactions on Image Processing, 7 (1), 27–41. https://doi.org/10.1109/83.650848
  48. Tokinova, R.P. (2008) Phylum Plathelminthes. In: Adrianov, A.V. (Ed.), Biota of the Russian Waters of the Sea of Japan. Vol. 6. Dalnauka, Vladivostok, pp. 8–70, pls. I–IX.
  49. Tsuchiya, M. & Nishihira, M. (1985) Islands of Mytilus as a habitat for small intertidal animals: effect of island size on community structure. Marine Ecology Progress Series, 25, 71–81. https://doi.org/10.3354/meps025071
  50. Tsuyuki, A., Oya, Y., Jimi, N., Hookabe, N., Fujimoto, S. & Kajihara, H. (2023) Theama japonica sp. nov., an interstitial polyclad flatworm showing a wide distribution along Japanese coasts. Zoological Science, 40 (3), 262–272. https://doi.org/10.2108/zs220105
  51. Tsuyuki, A., Yoshida, R. & Oya, Y. (2025) Description of a new species of Didangia Faubel, 1983 (Platyhelminthes: Polycladida: Didangiidae), with a suggestion for the function of its unique penis stylet based on morphology. Zoomorphology, 144 (2), 39. https://doi.org/10.1007/s00435-025-00722-6
  52. Tyler, S., Schilling, S., Hooge, M. & Bush, L.F. (Comp.) (2006–2025) Turbellarian taxonomic database. Version 2.2. Available from: http://turbellaria.umaine.edu (accessed 1 January 2025)
  53. Van Dover, C.L., Humphris, S.E., Fornari, D., Cavanaugh, C.M., Collier, R., Goffredi, S.K., Hashimoto, J., Lilley, M.D., Reysenbach, A.L., Shank, T.M., VonDamm, K.L., Banta, A., Gallant, R.M., Götz, D., Green, D., Hall, J., Harmer, T.L., Hurtado, L.A., Johnson, P., McKiness, Z.P., Meredith, C., Olson, E., Pan, I.L., Turnipseed, M., Won, Y., Young, C.R. & Vrijenhoek, R.C. (2001) Biogeography and ecological setting of Indian Ocean hydrothermal vents. Science, 294, 818–823. https://doi.org/10.1126/science.1064574
  54. Yeri, M. & Kaburaki, T. (1918) Description of some Japanese polyclad Turbellaria. Journal of the College of Science, Imperial University of Tokyo, 39 (9), 1–54.

How to Cite

Oya, Y., Hookabe, N., Jimi, N., Furushima, Y. & Fujiwara, Y. (2025) Description of a new bathyal species of Notocomplana (Platyhelminthes, Polycladida) collected from Bathymodiolus aggregations in a deep-sea hydrocarbon seep. Zootaxa, 5722 (2), 265–277. https://doi.org/10.11646/zootaxa.5722.2.6