Biodiversity of polychaetes with revision of Trichobranchidae and Antarctic Ampharetidae under consideration of cryptic speciation processes in the Southern Ocean

In course of the expeditions ANDEEP I-III and ANDEEP-Systco (2002, 2005, 2007/08) several thousand polychaetes have been sampled from the Weddell Sea and adjacent basins. In this project the analyses of biodiversity data, especially from the expedition ANDEEP-SYSTCO, is focussing especially on coupling processes from water surface to the deep-sea floor. Results will be correlated to biotic (plankton blossoms, food income, feeding ecology) and abiotic (geophysical and oceanographic data) factors that were studied in the aftermath of the expedition by different work groups. Additionally, the taxonomy, zoo- and phylogeography of the polychaete families Ampharetidae and Trichobranchidae, both abundant and speciose in all deep-sea samples, will form a major part of the project, in that species found in the deep Southern Ocean will be thoroughly revisited. In case of the Trichobranchidae a world-wide revision is desired in the long term. Haplotype diversity and distribution of selected species will be studied with the help of nuclear, mitochondrial and, partially, microsatellite markers to gain closer insight into actual horizontal and vertical distribution ranges, dispersal potential, and possible refugia.



Fig.1: Terebellides sp. 2 – yet undescribed species of Terebellidae from Southern Ocean

For biodiversity analyses the boxcorer samples from the expedition ANDEEP-SYSTCO (2007/08) positioned on a transect alongside the Greenwich Meridian have been investigated. One station in the polar front was revisited after a period of almost two months (stations 13 and 85). Station 39 was situated on top of the seamount Maud Rise. The samples yielded a total of 847 specimens from 31 families and 86 species. The most abundant and speciose families, as known from former SO samples and deep-sea samples world-wide, were the Spionidae , Cirratulidae, and Ampharetidae. First diversity measures showed that station 17 (Atka Bay slope) was most divers. The revisited station 13 and 85 show very similarities in diversity and species composition. Maud Rise (39) in contrast is characterized by median diversity and comparably low evenness, mainly resulting from the dominant abundance of the spionid Prionospio sp. 1 with 69 individuals.



Fig.2: Screenshot of sequence with tandem repeat (‘AG’) in Terebellides sp. 2

During the preceding funding period main focus in the taxonomic analyses was laid on the Trichobranchidae. A four week stay at the Australian Museum, Sydney in collaboration with Dr. Pat Hutchings has served to gain intensive insight in the usefulness and variability of taxonomic characters of Trichobranchidae. Based on numerous specimens and type material of Australian, Atlantic and Californian Trichobranchidae morphological characters could be classified to be applicable for different taxonomic levels (plesiomorphic, generic, species, specimen). Surprising the number of hooks, formerly always used as taxonomic character, seems to be highly variable within species and thus holds no relevant information for species distinction. The same seems to account for the number of abdominal segments. With help of this classification a new species of Terebellides could be distinguished and the SO Trichobranchidae in ANDEEP and ANDEEP-SYSTCO samples could be reliably sorted and identified.



Fig.3: Großkastengreifer-Stationen ANDEEP-SYSTCO (2007/08 mit RV Polarstern)

To date DNA extraction of 308 species are achieved (Ampharetidae, Trichobranchidae, Glyceridae). PCRs and sequencing is currently in progress for 16S rDNA when no mitochondrial gene sequence is yet achieved. For specimens with ready mitochondrial sequences (16S rDNA or CO I) sequencing of 28S nuclear DNA is in progress (e.g., Glycera kerguelensis). Results on mitochondrial markers already indicated cryptic speciation in Glycera kerguelensis while those from Trichobranchidae so far support the identification of the specimens. First results for the Ampharetidae are only very preliminary to date. It is however already visible we find far distribution of haplotypes on a vertical and horizontal scale.

In collaboration with Dr. F. Leese and his partners during the project MA 3684/2-1 microsatellites are currently being designed for the genus Terebellides. Observations of sequences have yielded at sixteen potential microsatellite. The quality and variability of these tandem repeats however have yet to be uncovered.

Scientists

Myriam Schüller,
Eileen Wilmsen
Animal Evolution, Ecology and Biodiversity
Ruhr Universität Bochum

Research areas

Weddell Sea and Polar Front (continental slope to deep sea)

Publications

Schüller M, Wägele JW, 2005. Redescription of Ischyromene lacazei Racovitza, 1908 (Isopoda: Sphaeromatidae) from the Mediterranean coast of southern France. Organisms, Diversity and Evolution 5, Electronic Supplement. 1-14.

Schüller M, Hilbig B, 2007. Three new species of the genus Oligobregma (Polychaeta, Scalibregmatidae) from the Scotia and Weddell Seas (Antarctica). Zootaxa 1391. 35-45.

Schüller M, Ebbe B, 2007. Global distributional patterns of selected deep-sea Polychaeta (Annelida) from the Southern Ocean. Deep-Sea Research II, 54. 1737-1751.

Schüller M, 2007. Biodiversity and Zoogeography of the Polychaeta (Annelida) in the deep Weddell Sea (Southern Ocean, Antarctica) and adjacent deep-sea basins). Dissertation. Faculty of Biology, Ruhr-University, Bochum. 1-248.

Linse K, Brandt A, Bohn J, Danis B, de Broyer C, Heterier V, Hilbig B, Janussen D, López González PJ, Schüller M, Schwabe E, Thomson MRA, 2007. Macro- and megabenthic communities in the bathyal and abyssal Weddell Sea (Southern Ocean). Deep-Sea Research II, 54. 1848-1863.

Schüller M, 2008. New polychaete species collected during the expeditions ANDEEP I, II, and III to the deep Atlantic sector of the Southern Ocean in the austral summers 2002 and 2005 – Ampharetidae, Opheliidae, and Scalibregmatidae. Zootaxa 1705, 51-68.

Schüller M, 2008. Polychaeta (Annelida) of the Deep Southern Ocean (Antarctica) – Biodiversity and Zoogeography. VDM Verlag Dr. Müller, Saarbrücken. 1-209.

Schüller M, Ebbe B, Wägele JW, 2009. Community structure and diversity of polychaetes (Annelida) in the deep Weddell Sea (Southern Ocean) and adjacent basins. Marine Biodiversity 39(2), 95-108. DOI: 10.1007/s12526-009-0009-4

Brandt A, Linse K, Schüller M, 2009. Bathymetric distribution of Southern Ocean macrofaunal taxa: Bivalvia, Gastropoda, Isopoda and Polychaeta. Deep-Sea Research I 56, 2013-2025.

Schüller M, Hutchings PA, 2010. New insights in the taxonomy of Trichobranchidae (Polychaeta) with description of a new Terebellides species. Zootaxa 2395, 1-16.

Schüller M, 2011. Evidence for a role of bathymetry and emergence in speciation in the genus Glycera (Glyceridae, Polychaeta) from the deep Eastern Weddell Sea. Polar Biology 34, 549-564. doi:10.1007/s00300-010-0913-x

Würzberg L, Brandt A, Peters J, Schüller M, 2011. Diet insights of deep-sea polychaetes derived from fatty acid analyses. Deep-Sea Research II 8, 153-162. doi:10.1016/j.dsr2.2010.10.014

Brandt A, Bathmann U, Brix S, Cisewski B, Flores H, Göcke C, Janussen D, Krägefsky S, Kruse S, Leach H, Linse K, Pakhomov E, Peeken I, Riehl T, Sauter E, Sachs O, Schüller M, Schroedl M, Schwabe E, Strass V, van Franeker J, Wilmsen E, 2011. Maud Rise – A snapshot through the water column. In Deep-Sea Research II. doi:10.1016/j.dsr2.2011.01.008 (in press)

Wilmsen E, Schüller M, 2011. Diversity and distribution of Polychaeta in deep Antarctic and Subantarctic waters along the Greenwich meridian. In Deep-Sea Research II. (in press)

Brandt A, De Broyer C, Ebbe B, Vanreusel A, Ellingsen KE, Gooday AJ, Janussen D, Kaiser S, Linse K, Schueller M, Thomson MRA, Tyler PA. The biodiversity of the deep Southern Ocean benthos. In: Antarctica: An Extreme Environment in a Changing World. Philosophical Transactions of the Royal Society of London - submitted

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Research funding organisation

German Research Foundation

Project number: SCHU 2443-2/1,2
Funding period: 01.10.2008 – 30.09.2010