Abstract
We describe two new species of spherical single-chambered ('saccamminid') foraminifera from the bathyal and abyssal Weddell Sea (Southern Ocean), collected in epibenthic sledge and Agassiz trawl samples obtained during the 2005 ANDEEP III campaign. Both are assigned to Leptammina gen. nov. The new genus is similar in overall test morphology to Saccammina Carpenter, 1869; it is distinguished mainly by its test wall, which is delicate, flexible and composed of fine mineral grains, rather than being rigid and coarsely agglutinated. In Leptammina grisea gen. et sp. nov., the test wall is relatively thick, grayish with a violet tinge and a dull surface; the cytoplasm is dark greenish. In Leptammina flavofusca gen. et sp. nov., the test is yellowish brown, with a very finely, almost transluscent agglutinated wall; the cytoplasm is pale yellowish. Both species have prominent circular apertures. Maximum likelihood phylogenetic analysis of SSU rRNA gene data showed that both species group together with an undescribed shallow-water Antarctic species (“silver saccamminid”) in a very strongly supported clade (100 %). Leptammina grisea gen. et sp. nov. is a relatively uncommon species (29 specimens from 3 stations), found at 1580–4822 m depth in the central and north–western Weddell Sea; Leptammina flavofusca gen. et sp. nov. is common (398 specimens from 4 stations) at depths of 3138–4795 m in the central Weddell Sea and off Kapp Norvegia. Both species are presently known only from ANDEEP III samples.References
Arnold, Z. (1982) Psammophaga simplora n. gen., n. sp., a polygenomic Californian saccamminid. Journal of Foraminiferal Research 12, 72–78.
Brady, H.B. (1879) Notes on some of the Reticularian Rhizopoda of the "Challenger" Expedition. Part 1. On new or little known arenaceous types. Quarterly Journal of Microscopical Science, new ser. 19, 20–63.
Brady, H.B. (1884) Report on the foraminifera dredged by H. M. S. Challenger, during the years 1873–1876, in Report on the Scientific Results of the Voyage of the H. M. S. Challenger during the years 1873–1876, Zoology, v. 9, xxi+813 pp , 1 map, 115 pls.
Brandt, A., Brix, S., Brökeland, W., Cedhagen, T., Choudhury, M., Cornelius, N., Danis, B., De Mesel, I., Diaz, R.J., Gillan, D.C., Ebbe, B., Howe, J., Janussen, D., Kaiser, S., Linse, K., Malyutina, M., Brandão, S.N., Pawlowski, J., Raupach, M., Vanreusel, A. & Gooday, A.J. (2007) The Southern Ocean deep sea: first insights into biodiversity and biogeography. Nature 447, 307–311.
Carpenter, W.B. (1869) On the rhizopodal fauna of the deep sea. Proceedings of the Royal Society of London 18, 59–62.
Carpenter, W.B. (1875) The Microscope and Its Revelations, 5th ed., J. & A. Churchill, London, xxxii+848 pp., 25 pls.
Cedhagen, T. & Pawlowski, J. (2002) Toxisarcon synsuicidica n. gen., n. sp., a large monothalamous foraminiferan from the west coast of Sweden. Journal of Foraminiferal Research 32, 351–357.
Cornelius, N. & Gooday, A.J. (2004) "Live" (stained) deep-sea benthic foraminiferans in the western Weddell Sea: trends in abundance, diversity and taxonomic composition along a depth transect. Deep-Sea Research II 51, 1571–1602.
Cushman, J.A. (1910) A monograph of the foraminifera of the North Pacific Ocean. Pt. 1. Astrorhizidae and Lituolidae. Bulletin of the United States National Museum 71(1), 1–134.
Dahlgren, L. (1962) A new monothalamous foraminifer, Ovammina opaca n.gen., n.sp., belonging to the family Saccamminidae. Zoologiska Bidrag från Uppsala 33, 197–200 + pl.
Gooday, A.J. (1986) Soft-shelled Foraminifera in meiofaunal samples from the bathyal northeast Atlantic. Sarsia, 71, 275–287.
Gooday, A.J. (1996) Epifaunal and shallow infaunal foraminiferal communities at three abyssal NE Atlantic sites subject to differing phytodetritus input regimes. Deep-Sea Research I, 43, 1395–1421.
Gooday, A.J.. (2002) Organic-walled allogromiids: aspects of their occurrence, diversity and ecology in marine habitats. Journal of Foraminiferal Research, 32, 384–399.
Gooday, A.J., Hughes, J.A., 2002. Foraminifera associated with phytodetritus deposits at a bathyal site in the northern Rockall Trough (NE Atlantic): seasonal contrasts and a comparison of stained and dead assemblages. Marine Micropaleontology, 46, 83–110.
Gooday, A.J. & Pawlowski, J. (2004) Conqueria laevis gen. and sp. nov., a new soft-walled monothalamous foraminiferan from the deep Weddell Sea. Journal of the Marine Biological Association of the United Kingdom 84, 919–924.
Gooday, A.J., Bernhard, J.M., Levin, L.A. & Suhr. S.B., (2000) Foraminifera in the Arabian Sea oxygen minimum zone and other oxygen deficient settings: taxonomic composition, diversity, and relation to metazoan faunas. Deep-Sea Research II, 47, 25–54.
Gooday, A.J., Bowser, S.S. & Bernhard, J.M. (1996) Benthic foraminiferal assemblages in Explorer’s Cove, Antarctica: a shallow water site with deep sea characteristics. Progress in Oceanography, 37, 219–267.
Gooday, A.J., Bowser, S.S., Cedhagen, T., Hald, M., Korsun, S. & Pawlowski, J. (2005) Soft-walled monothalamous foraminifera and gromids from western Svalbard fjords: a preliminary report. Marine Biology Research 1, 290–312.
Gooday, A.J., Cedhagen, T. & Cornelius, N. (2006) Diversity and biogeography of deep-sea benthic foraminifera - a combined molecular and morphological approach. Sonderforschungsbereich für Polarforschung. Pp. 89–94.
Gooday, A.J., Cedhagen, T., Kamenskaya, O.E. & Cornelius, N. (2007a) The biodiversity and biogeography of komokiaceans and other enigmatic foraminiferan-like protists in the bathyal and abyssal Southern Ocean. Deep-Sea Research Part II, 54, 1691–1719.
Gooday, A.J., Holzmann, M., Guiard, J., Cornelius, N. & Pawlowski, J. (2004a) A new foraminiferan from 1000 to 6300 m water depth in the Weddell Sea: morphological and molecular characterisation. Deep-Sea Research II 51, 1603–1616.
Gooday, A.J.,Hori, S., Todo, Y., Okamoto, T., Kitazato, H., Sabbatini, A. (2004b) Soft-walled, monothalamous benthic foraminiferans in the Pacific, Indian and Atlantic Oceans: aspects of biodiversity and biogeography. Deep-Sea Research I, 51, 33–53
Gooday, A.J., Kamenskaya, O.E. & Cedhagen, T. (2007b) New and little-known Komokiacea (Foraminifera) from the Weddell Sea and adjacent areas of the Southern Ocean. Zoological Journal of the Linnean Society 151, 219–251.
Gooday, A.J., Kitazato, H., Hori, S., Okamoto, T. (2001) Monothalamous soft-shelled foraminifera at an abyssal site in the North Pacific: a preliminary report. Journal of Oceanography, 57, 377–384.
Guindon, S. & Gascuel, O., 2003. A simple, fast, and accurate algorithm to estimate large phylogenies by maximum likelihood. Systematic Biology 52, 696–704.
Hedley, R.H. (1962) The significance of an "inner chitinous lining" in saccamminid organization with special reference to a new species of Saccammina (Foraminifera) from New Zealand. New Zealand Journal of Science 5, 375–389.
Heron-Allen, E. & Earland, A. (1932) Some new foraminifera from the South Atlantic: IV. Four new genera from South Georgia. Journal of the Royal Microscopical Society of London, ser. 3, 52, 253–261.
Höglund, H. (1947) Foraminifera in the Gullmar fjord and the Skagerak. Zoologiska Bidrag från Uppsala 26, 1–328 + 32 pls.
Lee, J.J., Pawlowski, J., Debenay, J.-P., Whittaker, J., Banner, F., Gooday, A.J., Teldal, O.S., Haynes, J. & Faber, W.W. (2000) Phylum Granuloreticulosa Lee, 1990. In: Lee, J.J., Leedale, G.F. & Bradbury, P. (Eds.). An Illustrated Guide to the Protozoa (Second edition). Society of Protozoologists. Pp, 872–951.
Lena, H. (1974) Dahlgrenia patagoniensis gen. nov., sp. nov. (Foraminifera, Saccaminidae). Physis, Buenos Aires (Sect. A) 33(86), 9–16.
Lena, H. and D. Haman (1980). Dahlgreniella nom. nov. for the genus Dahlgrenia Lena (Foraminifera, Saccamminidae). Revista Española de Micropaleontología 12(2), 178.
Loeblich, A.R. & Tappan, H. (1987) Foraminiferal Genera and their Classification. Van Nostrand Reinhold Company, New York, 2 vols, 970 pp. + 847 pls.
Mikhalevich, V.I. (2004) The general aspects of the distribution of Antarctic foraminifera. Micropaleontology, 50, 179–194.
Nozawa, F., Kitazato, H. Tsuchiya, M., Gooday, A.J., 2006. ‘Live’ benthic foraminifera at an abyssal site in the equatorial Pacific nodule province: abundance, diversity and taxonomic composition. Deep-Sea Research I. 53, 1406–1422.
Nyholm, K.-G. (1974) New monothalamous foraminifera. Zoon 2, 117–122.
Pawlowski, J., Holzmann, M., Berney, C., Fahrni, J., Cedhagen, T. & Bowser, S.S. (2002) Phylogeny of allogromiid Foraminifera inferred from SSU rRNA gene sequences. Journal of Foraminiferal Research 32(4), 334–343.
Pawlowski, J., Holzmann, M., Berney, C., Fahrni, J., Gooday, A.J., Cedhagen, T. Habura, A. & Bowser, S.S. (2003) The evolution of early Foraminifera. Proceedings of the National Academy of Sciences (PNAS) 100(20), 11494–11498.
Pawlowski, J., Fahrni, J.F., Guiard, J., Conlan, K., Hardecker, J., Habura, A. & Bowser, S.S. (2005) Allogromiid foraminifera and gromiids from under the Ross Ice Shelf: morphological and molecular diversity. Polar Biology 28(7), 514–522.
Pawlowski, J., Majewski, W., Longet, D., Guiard, J., Cedhagen, T., Gooday, A.J., Korsun, S., Habura, A.A. & Bowser, S.S. (2008) Genetic differentiation between Arctic and Antarctic monothalamous foraminifera. Polar Biology, 31, 1205–1216.
Sabbattini, A., Pawlowski, J., Gooday, A.J., Piraino, S., Bowser, S.S., Morigi, C. & Negri, A. (2004) Vellaria zuccellii sp. nov. a new monothalamous foraminifer from Terra Nova Bay, Antarctica. Antarctic Science 16(3), 307–312.
Saidova, Kh.M. (1975) Bentosnye Foraminifery Tikhogo Okeana. Institut Okeanologii P.P. Shirshova, Akademiya Nauk SSSR, Moscow, 3 vols, 875 pp.
Sen Gupta, B.K. (1999) Systematics of modern Foraminifera. In: Sen Gupta, B.K. (Ed.). Modern Foraminifera. Kluwer Academic Publishers, Norwell MA, pp. 403–422.