Abstract
This report provides a checklist of the echiurans from the Atlantic Ocean and maps their distribution. Investigations on the taxonomy of this group since the publication of the monograph by Stephen and Edmonds (1972) on the phyla Sipuncula and Echiura have yielded two new genera, 12 new species and 13 new records. Currently the echiuran fauna of the Atlantic comprises three families, 25 genera and 63 species. The family Bonelliidae contains 35 species in 18 genera; the Echiuridae is represented by six genera and 27 species, and the Urechidae by a single species Urechis chilensis (Müller). This study shows that the Atlantic has a relatively high species diversity, comprising about 38% of the known world fauna. Bonelliids alone comprise about 56% of the echiuran fauna of the Atlantic. An analysis of distribution is given in relation to general biogeographic regions and faunistic provinces. Dichotomous keys for the identification of genera and species of echiurans from the Atlantic is provided. The North Temperate component is the richest and most diverse, making up about 68% of the Atlantic echiuran fauna; 25 species have been recorded from within the tropics; and the South Temperate component is poorly represented, with only about 19% of the total fauna. The cosmopolitan component is also poorly represented, with only four species, so far, known. Thirteen species of echiurans are provisionally considered to be endemic to the Atlantic. Members of the Echiuridae are usually shallow-water inhabitants of intertidal and subtidal zones while bonelliids exhibit a higher species richness on deeper bottoms of all oceans, mostly at depths of 1000–6000 m in the Atlantic.References
Amor, A. (1976) Genera and species of Echiura known from South America. In: Rice, M.E. & Todorovic, M. (eds), Proceedings of the International Symposium on the Biology of the Sipuncula and Echiura. Vol. 2. Naucno Delo Press, Belgrade. pp. 119–125.
Biseswar, R. (1992) Some deep-sea echiurans of the North East Atlantic. Bulletin du Muséum national d’Histoire naturelle, sér. 4, A, 14, 639–654.
Biseswar, R. (2005) Report on some deep-sea echiurans (Echiura) of the North-East Atlantic. Zoosystema, 27, 37–46.
Biseswar, R. (2006) Additions to the deep-sea echiuran (Echiura) fauna of the North-East Atlantic. Zoosystema, 28, 853–864.
Briggs, J.C. (1974) Marine Zoogeography. McGraw-Hill, New York. 475 pp.
DattaGupta, A.K. (1981) Atlantic echiurans. Part 1. Report on twenty-two species of deep-sea echiurans of the North and the South Atlantic Oceans. Bulletin du Muséum national d’Histoire naturelle, sér. 4, A, 3, 353–378.
DattaGupta, A.K. & Menon, P.K.B. (1971) Anatomical notes on four species of Ochetostoma Leuckart & Rüppell (Echiura) together with a list of the species of the genus. Records of the Zoological Survey of India, 65, 173–182.
Fischer, W. (1895) Die Gephyreen des naturhistorischen Museums zu Hamburg. Abhhandlungen aus dem Gebiet der Naturwissenschaften, Hamburg, 13, 1–24.
Fischer, W. (1914) Weitere Mitteilungen über de Gephyreen des naturhistorischen (zoologischen) Museums zu Hamburg. Jahrbuch der Hamburgischen Wissenschaftlichen Anstalten, 31, 1–28.
Fisher, W.K. (1947) New genera and species of echiuroid and sipunculoid worms. Proceedings of the United States National Museum, 97, 351–372.
Herdman, W.A. (1897) Note on a new British echiuroid gephyreen with remarks on the genera Thalassema and Hamingia. Quarterly Journal of microscopical Science, n.s., 40, 367–384.
Mathew, J. (1976) The geographic distribution of echiurans in world oceans with special reference to the Indian forms. In: Rice, M.E. & Todorovic, M. (eds), Proceedings of the International Symposium on the Biology of the Sipuncula and Echiura. Vol. 2. Naucno Delo Press, Belgrade, pp. 127–133.
Newby, W.W. (1940) The embryology of the echiuroid worm Urechis caupo. Memoirs of the American Philosophical Society, 16, 1–213.
Nishikawa, T. (1998) Nomenclatural remarks on the family-group names of the phylum Echiura. Proceedings of the Biological Society of Washington, 111, 249–256.
Nishikawa, T. (2002) Comments on the taxonomic status of Ikeda taenioides (Ikeda, 1904) with some amendments in the classification of the phylum Echiura. Zoological Science, 19, 1175–1180.
Saiz-Salinas, J.I., Dean, H.K. & Cutler, E.B. (2000) Echiura from Antarctic and adjacent waters. Polar Biology, 23, 661–670.
Scheltema, R.S. (1968) Dispersal of larvae by equatorial currents and its importance to the zoogeography of shoalwater tropical species. Nature, London, 217, 1159-1162.
Scheltema, R.S. & Hall, J.R. (1965) Trans-oceanic transport of sipunculid larvae belonging to the genus Phascolosoma. American Society of Zoologists, 5, 216.
Scheltema, R.S. & Hall, J.R. (1975) The dispersal of pelagosphaera larvae by ocean currents and the geographical distribution of sipunculans. In: Rice M.E. & Todorovic, M. (eds), Proceedings of the International Symposium on the Biology of the Sipuncula and Echiura. Vol. 1. Naucno Delo Press, Belgrade, pp. 103–115.
Selenka, E. (1885) Report of the Gephyrea collected by H.M.S. ‘Challenger’ during the years 1873–1876. Report of the Scientific Results of the Voyage of H.M.S. Challenger, 13(36), 1–25.
Stephen, A.C. (1941) The Echiuridae, Sipunculidae and Priapulidae collected by the ships of the Discovery Committee during the years 1926–1937. Discovery Report, 21, 235–260.
Stephen, A.C. (1956) Amalosoma eddystonense sp. n. a new species of Bonelliidae. Journal of the marine biological Association of the United Kingdom, 35, 605–608.
Stephen, A.C. (1960a) Echiuroidea and Sipunculoidea from Senegal, West Africa. Bulletin de l’Institut Français d’Afrique Noire, sér. A(2), 22, 512–520.
Stephen, A.C. (1960b) British echiurids (Echiuroidea), sipunculids (Sipunculoidea) and priapulids (Priapuloidea). With keys and notes for the identification of species. Synopses of the British Fauna, 12, 1–27.
Stephen, A.C. & Edmonds, S.J. (1972) The Phyla Sipuncula and Echiura. Trustees of the British Museum (Natural History), London, 528 pp.
Wesenberg-Lund, E. (1939a) Gephyreans from Swedish waters in the Museum of Natural History, Gotenburg. Goteborgs Kungliga Vetenskaps-och Vitterhets-Samhālles Handlingar, ser. B, 6, 1–35.
Wesenberg-Lund, E. (1939b) Norwegian Gephyrea from the collections of the Zoological Museum of Trondheim. Kongelige Norske Videnskabers Selskabs Skriftserie, 11, 26–29.
Wesenberg-Lund E. (1957) Sipunculoidea and Echiuroidea from West Africa, together with a bibliography on Gephyrea after 1920. Bulletin de l’Institut royal des Sciences naturelles de Belgique, 33(42), 1–24.
Wesenberg-Lund, E. (1959a) Sipunculoidea and Echiuroidea from tropical West Africa. Atlantide Report, 5, 177–210.
Wesenberg-Lund, E. (1959b) Campagne 1956 de la ‘Calypso’ dans le Golfe de Guinée et aux Iles Principé, São Tome et Annobon. Sipunculoidea and Echiuroidea. Annals of the Institute of Oceanography, Monaco, n.s., 37, 207–217.
Wilson, C.B. (1900) Our North American echiurids. A contribution to the habits and geographical range of the group. Biological Bulletin, 1, 163–178.
Zenkevitch, L.A. (1966) The systematics and distribution of abyssal and hadal (ultra-abyssal) Echiuroidea. Galathea Report, 8, 175–184.