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Published: 2021-09-20

Spirobranchus bakau sp. nov. from Singapore: yet another species of S. kraussii-complex (Polychaeta: Serpulidae)

Tropical Marine Science Institute, National University of Singapore, Singapore 119227, Singapore.
Tropical Marine Science Institute, National University of Singapore, Singapore 119227, Singapore.
Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney NSW 2010, Australia. Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia.
Yale-NUS College, National University of Singapore. Singapore 138527, Singapore.
Tropical Marine Science Institute, National University of Singapore, Singapore 119227, Singapore.
Tropical Marine Science Institute, National University of Singapore, Singapore 119227, Singapore.
Polychaeta 18S Cyt b integrative taxonomy mangrove West Johor Strait


The intertidal serpulid polychaete Spirobranchus kraussii was originally described from South Africa and has since been reported in numerous sub (tropical) localities around the world. Recently, however, S. kraussii was uncovered as a complex of morphologically similar and geographically restricted species, raising the need to revise S. cf. kraussii populations. We formally describe S. cf. kraussii from Singapore mangroves as Spirobranchus bakau sp. nov. based on morphological and molecular data. Despite their morphological similarities, Maximum Likelihood and Bayesian Inference analyses of 18S and Cyt b DNA sequence data confirm that S. bakau sp. nov. is genetically distinct from S. kraussii and other known species in the complex. Both analyses recovered S. bakau sp. nov. as part of a strongly supported clade (96% bootstrap, 1 posterior probability), comprising S. sinuspersicus, S. kraussii and S. cf. kraussii from Australia and Hawaii. Additionally, paratypes of S. kraussii var. manilensis, described from Manila Bay in the Philippines, were examined and elevated to the full species S. manilensis. Finally, we tested the hypothesis that fertilisation and embryonic development of S. bakau sp. nov. can occur under the wide range of salinities (19.6–30.9 psu) and temperatures (25–31°C) reported in the Johor Strait. Fertilisation success of ≥70% was achieved across a temperature range of 25–32°C and a salinity range of 20–32 psu. Embryonic development, however, had a narrower salinity tolerance range of 27–32 psu. Clarifying the taxonomic status of S. cf. kraussii populations reported from localities elsewhere in Singapore and Southeast Asia will be useful in establishing the geographical distribution of S. bakau sp. nov. and other members of the S. kraussii-complex.



  1. Allen, J.D. & Pechenik, J.A. (2010) Understanding the effects of low salinity on fertilization success and early development in the sand dollar Echinarachnius parma. The Biological Bulletin, 218 (2), 189–199.
    Baird, W. (1864) Description of several new species and varieties of Tubicolous Annelides: Tribe Limivora of Grube, in the collection of the British Museum. Journal of the Proceedings of Linnean Society, 8 (29), 10–22.
    Bastida-Zavala, J.R. (2008) Serpulids (Annelida: Polychaeta) from the Eastern Pacific, including a brief mention of Hawaiian serpulids. Zootaxa, 1722 (1), 1–61.
    Becker, K. (1993) Attachment strength and colonization patterns of two macrofouling species on substrata with different surface tension (in situ studies). Marine biology, 117 (2), 301–309.
    Belal, A.A.M. & Ghobashy, A.F.A. (2012) Settlement behaviour and description of the Lessepsian immigrant of the serpulid polychaete Pomatoleios kraussii in the Suez Bay. The Egyptian Journal of Aquatic Research, 38 (1), 23‒30.
    Blainville, H.D. (1818) Mémoire sur la classe des Sétipodes, partie des Vers à sang rouge de M. Cuvier, et des Annélides de M. de Lamarck. Bulletin des Sciences, par la Société Philomatique de Paris, 1818, 78‒85.
    Brandão, I.C. & Brasil, A.C.D.S. (2020) On a new species of Spirobranchus (Annelida: Serpulidae) and considerations on the genus along the Brazilian coast. Papéis Avulsos de Zoologia, 60, 1–17.
    Cai, Y., Hove, H.A. ten & Teo, S.L.M. (2004) Taxonomy and distribution of fouling serpulid polychaetes found in Singapore waters. 8th International Polychaete Conference, Madrid, Program & Abstracts, 40.
    Chan, J.Y., Lee, S.S., Rahim, S.Z.Z. & Teo, S.L.M. (2014) Settlement inducers for larvae of the tropical fouling serpulid, Spirobranchus kraussii (Baird, 1865) (Polychaeta: Annelida). International Biodeterioration and Biodegradation, 94, 192–199.
    Chénard, C., Wijaya, W., Vaulot, D., dos Santos, A.L., Martin, P., Kaur, A. & Lauro, F.M. (2019) Temporal and spatial dynamics of Bacteria, Archaea and protists in equatorial coastal waters. Scientific reports, 9 (1), 1–13.
    Chou, L.M. & Chia, L.S. (1991) The marine environment. In: Chia, L.S., Rahman, A. & Tay, D.B.H. (Eds.), The biophysical environment of Singapore. Singapore University Press, Singapore, pp. 155–184.
    Chou, L.M., Huang, D., Tan, K.S., Toh, T.C., Goh, B.P. & Tun, K. (2019) Singapore. In: Sheppard, C.R.C. (Ed.) World seas: an environmental evaluation. Vol. II. The Indian Ocean to the Pacific. Academic Press, London, pp. 539–558.
    Çinar, M.E. (2006) Serpulid species (Polychaeta: Serpulidae) from the Levantine coast of Turkey (eastern Mediterranean), with special emphasis on alien species. Aquatic Invasions, 1 (4), 223‒240.
    Corlett, R.T. (1992) The ecological transformation of Singapore, 1819-1990. Journal of biogeography, 19 (4), 411–420.
    Crisp, M. (1977) The development of the serpulid Pomatoleios kraussii (Annelida, Polychaeta). Journal of Zoology, 183 (2), 147‒160.
    Darling, J. & Carlton, J. (2018) A framework for understanding marine cosmopolitanism in the Anthropocene. Frontiers in Marine Science, 5, 293.
    Darriba, D., Taboada, G.L., Doallo, R. & Posada, D. (2012) jModelTest 2: more models, new heuristics and parallel computing. Nature Methods, 9 (8), 772.
    Day, J.H. (1961) The polychaete fauna of South Africa. Part 6. Sedentary species dredged off Cape coasts with a few new records from the shore. Zoological Journal of the Linnean Society, 44 (299), 463–560.
    Delorme, N.J. & Sewell, M.A. (2014) Temperature and salinity: two climate change stressors affecting early development of the New Zealand sea urchin Evechinus chloroticus. Marine Biology, 161 (9), 1999–2009.
    Dittmann, S., Rolston, A., Benger, S.N. & Kupriyanova, E.K. (2009) Habitat requirements, distribution and colonisation of the tubeworm Ficopomatus enigmaticus in the Lower Lakes and Coorong. Report for the South Australian Murray-Darling Basin Natural Resources Management Board, Adelaide, pp. 1–99.
    FAO (1999) Rural aquaculture in the Philippines. Document prepared by W. G. Yap. Regional Office for Asia and the Pacific, Bangkok, Thailand. FAO, Rome. Available from: (accessed 20 December 2020)
    Fauvel, P. (1923) Un nouveau serpulien d’eau saumatre Mercierella ng enigmatica n. sp. Bulletin de la Société Zoologique de France, 46, 424–430.
    Fauvel, P. (1932) Annelida Polychaeta of the Indian Museum, Calcutta. Memoirs of the Indian Museum, 12, 1–262.
    Fernández-Rodríguez, V., Londoño-Mesa, M.H. & Ramírez-Restrepo, J.J. (2016) Polychaetes from Red Mangrove (Rhizophora mangle) and their relationship with the water conditions in the Gulf of Urabá, Colombian Caribbean. Acta Biológica Colombiana, 21 (3), 611–618.
    Fiege, D. & Sun, R. (1999) Polychaeta from Hainan Island, South China Sea. Part I: Serpulidae (Annelida, Polychaeta, Serpulidae). Senckenbergiana Biologica, 79, 109–141.
    Gin, K.Y.H., Lin, X. & Zhang, S. (2000) Dynamics and size structure of phytoplankton in the coastal waters of Singapore. Journal of Plankton Research, 22 (8), 1465–1484.
    Glasby, C.J., Lee, Y.L. & Hsueh, P.W. (2016) Marine Annelida (excluding clitellates and siboglinids) from the South China Sea. Raffles Bulletin of Zoology, 34, 178–234.
    Gray, J.E. (1843) Fauna of New Zealand. Materials towards a fauna of New Zealand, Auckland Island, and Chatham Islands. In: Dieffenbach, E. (Ed.) Travels in New Zealand; with contributions to the geography, geology, botany and natural history of that country Vol. 2. John Murray, London, pp. 177–296.
    Grube, A.E. (1862) Mittheilungen über die Serpulen, mit besonderer Berücksichtigung ihrer Deckel. Jahresbericht und Abhandlungen der Schlesischen Gesellschaft in Breslau, 39, 53–69.
    Gründlingh, M.L., Hunter, I.T. & Potgieter, E. (1989) Bottom currents at the entrance to False Bay, South Africa. Continental Shelf Research, 9 (12), 1029–1048.
    Hall, T.A. (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series, 41, 95–98.
    Halt, M.N., Kupriyanova, E.K., Cooper, S.J. & Rouse, G.W. (2009) Naming species with no morphological indicators: species status of Galeolaria caespitosa (Annelida: Serpulidae) inferred from nuclear and mitochondrial gene sequences and morphology. Invertebrate Systematics, 23 (3), 205‒222.
    Haswell, W.A. (1883) On some new Australian tubicolous annelids. Proceedings of the Linnean Society of New South Wales, 7 (4), 633‒638.
    Hove, H.A. ten & Kupriyanova, E.K. (2009) Taxonomy of Serpulidae (Annelida, Polychaeta): the state of affairs. Zootaxa, 2036 (1), 1‒126.
    Hove, H.A. ten & Weerdenburg, J.C.A. (1978) A generic revision of the brackish-water serpulid Ficopomatus Southern 1921 (Polychaeta: Serpulinae), including Mercierella Fauvel 1923, Sphaeropomatus Treadwell 1934, Mercierellopsis Rioja 1945 and Neopomatus Pillai 1960. The Biological Bulletin, 154 (1), 96‒120.
    Hove, H.A. ten & Zibrowius, H. (1986). Laminatubus alvini gen. et sp. n. and Protis hydrothermica sp. n. (Polychaeta, Serpulidae) from the bathyal hydrothermal vent communities in the eastern Pacific. Zoologica Scripta, 15 (1), 21‒31.
    Hutchings, P. & Kupriyanova, E.K. (2018) Cosmopolitan polychaetes – fact or fiction? Personal and historical perspectives. Invertebrate Systematics, 32 (1), 1‒9.
    ICZN (1999) International Code of Zoological Nomenclature. 4th Edition. International Trust for Zoological Nomenclature, London, 306 pp.
    Imajima, M. & Hartman, O. (1964) The polychaetous annelids of Japan. Part 1. Occasional Papers of the Allan Hancock Foundation, 26, 1–237.
    Ishaq, S. & Mustaquim, J. (1996) Polychaetous annelids (order Sabellida) from the Karachi coast, Pakistan. Pakistan Journal of Marine Sciences, 5 (2), 161‒167.
    Jacinto, G.S., Velasquez, I.B., San Diego-McGlone, M.L., Villanoy, C.L. & Siringan, F.B. (2006) Biophysical Environment of Manila Bay—Then and Now. In: Wolanski, E. (Ed.), The Environment in Asia Pacific Harbours. Springer, Dordrecht, pp. 293‒307.
    Kazemi, Z., Hashim, N.B. & Ismail, M. (2013) Estimating the mean salinity, dissolved oxygen and temperature of the West of Johor Strait, Malaysia. Conference on Land and Water, Universiti Teknologi Malaysia, Skudai, 26 pp.
    Kazmi, Q.B. & Naushaba, R. (2013) Checklist of marine worms reported from Pakistani marine waters. Pakistan Journal of Nematology, 31 (2), 187–280.
    Kumar, S., Stecher, G., Li, M., Knyaz, C. & Tamura, K. (2018) MEGA X: molecular evolutionary genetics analysis across computing platforms. Molecular biology and evolution, 35 (6), 1547–1549.
    Kupriyanova, E.K. (1999) The taxonomic status of Serpula cf. columbiana Johnson, 1901 from the American and Asian coasts of the North Pacific Ocean (Polychaeta: Serpulidae). Ophelia, 50 (1), 21–34.
    Kupriyanova, E.K., Macdonald, T.A. & Rouse, G.W. (2006) Phylogenetic relationships within Serpulidae (Sabellida, Annelida) inferred from molecular and morphological data. Zoologica Scripta, 35 (5), 421–439.
    Lamarck, J.B. (1818) Histoire naturelle des Animaux sans Vertèbres, préséntant les caractères généraux et particuliers de ces animaux, leur distribution, leurs classes, leurs familles, leurs genres, et la citation des principales espèces qui s’y rapportent; precedes d’une Introduction offrant la determination des caracteres essentiels de l’Animal, sa distinction du vegetal et des autres corps naturels, enfin, l’Exposition des Principes fondamentaux de la Zoologie Vol. 5. Deterville, Paris, 612 pp.
    Larkin, M.A., Blackshields, G., Brown, N.P., Chenna, R., McGettigan, P.A., McWilliam, H., Valentin, F., Wallace, I.M., Wilm, A., Lopez, R., Thompson, J.D., Gibson, T.J. & Higgins, D.G. (2007) Clustal W and Clustal X version 2.0. Bioinformatics, 23, 2947–2948.
    Lavajoo, F. & Amrollahi-Biuki, N. (2015) Biological structure and the effect of temperature on embryonic stage of the Spirobranchus kraussii (Baird, 1865) (Annelida: Serpulidae) in Bandar Abbas in the Persian Gulf. Journal of the Persian Gulf, 6 (22), 49–60.
    Lehrke, J., Harry, A., Macdonald, T.A., Bartolomaeus, T. & Bleidorn, C. (2007) Phylogenetic relationships of Serpulidae (Annelida: Polychaeta) based on 18S rDNA sequence data, and implications for opercular evolution. Organisms Diversity & Evolution, 7 (3), 195–206.
    Li, C., Meng, Y., He, C., Chan, V., Yao, H. & Thiyagarajan, V. (2016) Mechanical robustness of the calcareous tubeworm Hydroides elegans: warming mitigates the adverse effects of ocean acidification. Biofouling, 32 (2), 191–204.
    Marenzeller, E. von (1885) Südjapanische Anneliden. II. Ampharetea, Terebellacea, Sabellacea, Serpulacea. Denkschrift der Königliche Akademie der Wissenschaften Wien (mathematische und naturwissenschaften Klasse), 49 (2), 197–224.
    Mörch, O.A.L. (1863) Revisio critica Serpulidarum. Et bidrag til rørormenes naturhistorie. Naturhistorisk Tidsskrift Henrik Krøyer, København, Series 3, 1, 347–470.
    Nishi, E. (1993) Ecological study of a sessile polychaete Pomatoleios kraussii (Baird) (Serpulidae, Sedentaria) at Haneji Inlet, Okinawa, with fouling species composition there. The Biological Magazine, Okinawa, 31, 29–40.
    Nóren, M. & Jordelius, U. (1999) Phylogeny of Prolecithophora (Platyhelminthes) inferred from 18S rDNA sequences. Cladistics, 15 (2), 103–112.
    Nygren, A. (2014) Cryptic polychaete diversity: a review. Zoologica Scripta, 43 (2), 172‒183.
    Okuda, S. (1937) Annelida Polychaeta in Onagawa Bay and its vicinity. I. Polychaeta Sedentaria. Scientific Reports of the Tôhoku Imperial University (4 Biology), 12, 45–69.
    Oliva, M., Mennillo, E., Barbaglia, M., Monni, G., Tardelli, F., Casu, V. & Pretti, C. (2018) The serpulid Ficopomatus enigmaticus (Fauvel, 1923) as candidate organisms for ecotoxicological assays in brackish and marine waters. Ecotoxicology and Environmental Safety, 148, 1096‒1103.
    Olivares, R.U., Tabeta, S. & Sombrito, E.Z. (2013) Tributyltin in marine sediments and Philippine green mussels (Perna viridis) in Manila Bay. Journal of Marine Science and Technology, 18 (2), 213‒219.
    Paxton, H. & Chou, L.M. (2000) Polychaetous annelids from the South China Sea. Raffles Bulletin of Zoology, 48, 209–232.
    Pazoki, S., Rahimian, H., Struck, T.H., Katouzian, A.R. & Kupriyanova, E.K. (2020) A new species of the Spirobranchus kraussii-complex (Annelida, Serpulidae) from the Persian Gulf and Gulf of Oman. Zootaxa, 4748 (3), 401–430.
    Pechenik, J.A., Pearse, J.S. & Qian, P.Y. (2007) Effects of salinity on spawning and early development of the tube-building polychaete Hydroides elegans in Hong Kong: not just the sperm’s fault? The Biological Bulletin, 212 (2), 151–160.
    Peria, J. & Pernet, B. (2019) Tolerance to salinity and thermal stress by larvae and adults of the serpulid annelid Ficopomatus enigmaticus. Invertebrate Biology, 138 (4), e12271.
    Perry, O., Bronstein, O., Simon-Blecher, N., Atkins, A., Kupriyanova, E.K., Hove, H.A. ten, Levy, O. & Fine, M. (2018) On the genus Spirobranchus (Annelida, Serpulidae) from the northern Red Sea, and a description of a new species. Invertebrate Systematics, 32 (3), 605–626.
    Pillai, T.G. (1960) Some marine and brackish-water serpulid Polychaeta from Ceylon, including new genera and species. Ceylon Journal of Science (Biological Sciences), 3 (1), 1–40.
    Pillai, T.G. (1965) Annelida Polychaeta from the Philippines and Indonesia. Ceylon Journal of Science (Biological Sciences), 8, 100–172.
    Pillai, T.G. (1971) Studies on a collection of marine and brackish-water polychaetous Annelida of the family Serpulidae from Ceylon. Ceylon Journal of Science (Biological Sciences), 9, 88–139.
    Pillai, T.G. (2009) Descriptions of new serpulid polychaetes from the Kimberleys of Australia and discussion of Australian and Indo-West Pacific species of Spirobranchus and superficially similar taxa. Records of the Australian Museum, 61, 93–199.
    Pineda, M.C., McQuaid, C.D., Turon, X., López-Legentil, S., Ordóñez, V. & Rius, M. (2012) Tough adults, frail babies: an analysis of stress sensitivity across early life-history stages of widely introduced marine invertebrates. PLoS One, 7 (10), e46672.
    Pixell, H.L.M. (1913) Polychaeta of the Indian Ocean, together with some species from the Cape Verde Islands. The Serpulidae, with a classification of the genera Hydroides and Eupomatus. Transactions of the Linnean Society of London. 2nd Series. Zoology, 16 (1), 69–92.
    Qiu, J.W. & Qian, P.Y. (1997) Combined effects of salinity, temperature and food on early development of the polychaete Hydroides elegans. Marine Ecology Progress Series, 152, 79–88.
    Rafinesque, S.C. (1815) Analyse de la nature ou Tableau de l’univers et des corps organisés. Aux deìpens de l’auteur, Palermo, 224 pp.
    Rambaut, A., Drummond, A.J., Xie, D., Baele, G. & Suchard, M.A. (2018) Posterior summarization in Bayesian phylogenetics using Tracer 1.7. Systematic biology, 67 (5), 901–904.
    Rao, L.M.V. (1969) Fouling serpulids from some Indian harbours. Journal of the Timber Development Association of India, 15 (2), 1–20.
    Rao, K.S. & Ganapati, P.N. (1986) Distribution pattern and abundance of bryozoa on rocky shores of Visakhapatnam, Bay of Bengal. In: Thompson, M.F., Sarojini, R. & Nagabhushanam, R. (Eds.), Biology of benthic marine organisms. Techniques and methods as applied to the Indian Ocean. Oxford & IBH Publ. Co. Pvt. Ltd, New Delhi, Bombay, Calcutta, pp. i–xxv + 1–608.
    Rioja, E. (1941) Estudios anelidologicos II. Observaciones acerca de varias especies del genero Hydroides Gunnerus (sensu Fauvel) de las costas Mexicanas del Pacifico. Anales del Instituto de Biologia, Mexico, 12 (1), 161–175.
    R Core Team (2019) R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna. Available from: (accessed 19 March 2020)
    Ronquist, F., Teslenko, M., Van Der Mark, P., Ayres, D.L., Darling, A., Höhna, S., Larget, B., Liu, L., Suchard, M.A. & Huelsenbeck, J.P. (2012) MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology, 61 (3), 539–542.
    Rouse, G.W. & Kupriyanova, E.K. (2021) Laminatubus (Serpulidae, Annelida) from eastern Pacific hydrothermal vents and methane seeps, with description of two new species. Zootaxa, 4915 (1), 1–27.
    Rzhavsky, A. (1994) On the morphoecology of spirorbid tubes (Polychaeta: Spirorbidae). Ophelia, 39 (3), 177–182.
    Sánchez Ovando, J.P. (2019) Revisión de las especies del género Spirobranchus Blainville, 1818 (Polychaeta: Serpulidae) de América tropical. Bachelor’s thesis, Universidad del Mar, Puerto Ángel, Oaxaca, México, 99 pp.
    Schmarda, L.K. (1861) Neue Wirbellose Thiere: Beobachted und Gesammelt auf einer Reise um die Erdr 1853 bis 1857. In: Turbellarien, Rotatorien und Anneliden. Wilhelm Engelmann, Leipzig, 164 pp.
    Simon, C.A., van Niekerk, H.H., Burghardt, I., Hove, H.A. ten & Kupriyanova, E. (2019) Not out of Africa: Spirobranchus kraussii (Baird, 1865) is not a global fouling and invasive serpulid of Indo-Pacific origin. Aquatic Invasions, 14 (2), 221–249.
    Southern, R. (1921) Polychaeta of the Chilka Lake and also of fresh and brackish waters in other parts of India. Memoirs of the Indian Museum, 5 (8), 563–659.
    Spalding, M.D., Fox, H.E., Allen, G.R., Davidson, N., Ferdaña, Z.A., Finlayson, M.A.X., Halpern, B.S., Jorge, M.A., Lombana, A.L., Lourie, S.A. & Martin, K.D. (2007) Marine ecoregions of the world: a bioregionalization of coastal and shelf areas. BioScience, 57 (7), 573–583.
    Stamatakis, A. (2014) RAxML version 8: a tool for phylogenetic analysis and post analysis of large phylogenies. Bioinformatics, 30 (9), 1312–1313.
    Sun, Y., Hove, H.A. ten & Qiu, J.W. (2012) Serpulidae (Annelida: Polychaeta) from Hong Kong. Zootaxa, 3424 (1), 1–42.
    Sun, Y., Wong, E., Tovar-Hernández, M.A., Williamson, J.E. & Kupriyanova, E.K. (2016) Is Hydroides brachyacantha (Serpulidae: Annelida) a widespread species? Invertebrate Systematics, 30 (1), 41–59.
    Swami, B.S. & Udhayakumar, M. (2010) Seasonal influence on settlement, distribution and diversity of fouling organisms at Mumbai harbour. Indian Journal of Marine Sciences, 39 (1), 57–67.
    Tan, K.S., Acerbi, E. & Lauro, F.M. (2016) Marine habitats and biodiversity of Singapore’s coastal waters: A review. Regional Studies in Marine Science, 8, 340–352.
    Verween, A., Vincx, M. & Degraer, S. (2007) The effect of temperature and salinity on the survival of Mytilopsis leucophaeata larvae (Mollusca, Bivalvia): The search for environmental limits. Journal of Experimental Marine Biology and Ecology, 348 (1–2), 111–120.
    Vinn, O., Hove, H.A. ten, Mutvei, H. & Kirsimäe, K. (2008) Ultrastructure and mineral composition of serpulid tubes (Polychaeta, Annelida). Zoological Journal of the Linnean Society, 154 (4), 633–650.
    Wang, J. & Huang, Z. (1993) Fouling polychaetes of Hong Kong and adjacent waters. Asian marine biology, 10, 1–12.
    Westheide, W. & Schmidt, H. (2003) Cosmopolitan versus cryptic meiofaunal polychaete species: an approach to a molecular taxonomy. Helgoland Marine Research, 57 (1), 1–6.