title: Diversity in a Cold Hot-Spot: DNA-Barcoding Reveals Patterns of Evolution among Antarctic Demosponges (Class Demospongiae, Phylum Porifera).
abstract: BACKGROUND
  The approximately 350 demosponge species that have been described from Antarctica represent a faunistic component distinct from that of neighboring regions. Sponges provide structure to the Antarctic benthos and refuge to other invertebrates, and can be dominant in some communities. Despite the importance of sponges in the Antarctic subtidal environment, sponge DNA barcodes are scarce but can provide insight into the evolutionary relationships of this unique biogeographic province.
  
  
  RESULTS
  We sequenced the standard barcoding COI region for a comprehensive selection of sponges collected during expeditions to the Ross Sea region in 2004 and 2008, and produced DNA-barcodes for 53 demosponge species covering about 60% of the species collected. The Antarctic sponge communities are phylogenetically diverse, matching the diversity of well-sampled sponge communities in the Lusitanic and Mediterranean marine provinces in the Temperate Northern Atlantic for which molecular data are readily available. Additionally, DNA-barcoding revealed levels of in situ molecular evolution comparable to those present among Caribbean sponges. DNA-barcoding using the Segregating Sites Algorithm correctly assigned approximately 54% of the barcoded species to the morphologically determined species.
  
  
  CONCLUSIONS
  A barcode library for Antarctic sponges was assembled and used to advance the systematic and evolutionary research of Antarctic sponges. We provide insights on the evolutionary forces shaping Antarctica's diverse sponge communities, and a barcode library against which future sequence data from other regions or depth strata of Antarctica can be compared. The opportunity for rapid taxonomic identification of sponge collections for ecological research is now at the horizon.
authors.affiliation: Department of Earth- & Environmental Sciences, Palaeontology and Geobiology, Ludwig-Maximilians-Universtität München, Richard-Wagner Str. 10, D-80333, München, Germany.
authors.forename: Sergio
authors.initials: S
authors.lastname: Vargas
authors.affiliation: National Centre for Coasts and Oceans, National Institute of Water and Atmospheric Research, Private Bag 99940, Newmarket, Auckland, 1149, New Zealand.
authors.forename: Michelle
authors.initials: M
authors.lastname: Kelly
authors.affiliation: National Centre for Coasts and Oceans, National Institute of Water and Atmospheric Research, Private Bag 14901, Wellington, New Zealand.
authors.forename: Kareen
authors.initials: K
authors.lastname: Schnabel
authors.affiliation: National Centre for Coasts and Oceans, National Institute of Water and Atmospheric Research, Private Bag 14901, Wellington, New Zealand.
authors.forename: Sadie
authors.initials: S
authors.lastname: Mills
authors.affiliation: National Centre for Coasts and Oceans, National Institute of Water and Atmospheric Research, Private Bag 14901, Wellington, New Zealand.
authors.forename: David
authors.initials: D
authors.lastname: Bowden
authors.affiliation: Department of Earth- & Environmental Sciences, Palaeontology and Geobiology, Ludwig-Maximilians-Universtität München, Richard-Wagner Str. 10, D-80333, München, Germany; GeoBio-CenterLMU, Richard-Wagner Str. 10, D-80333, München, Germany; Bavarian State Collections of Palaeontology and Geology, Richard-Wagner Str. 10, D-80333, München, Germany.
authors.forename: Gert
authors.initials: G
authors.lastname: Wörheide
mesh_terms: D000818:Animals; D000864:Antarctic Regions; D044822:Biodiversity; D016000:Cluster Analysis; D058893:DNA Barcoding, Taxonomic; D019143:Evolution, Molecular; D010802:Phylogeny; D011161:Porifera / Q000145:classification* / Q000235:genetics*