title: Phylogenetic relationships among NE Atlantic Plocamionida Topsent (1927) (Porifera, Poecilosclerida): under-estimated diversity in reef ecosystems.
abstract: BACKGROUND
  Small and cryptic sponges associated with cold-water coral reefs are particularly numerous and challenging to identify, but their ecological and biochemical importance is likely to compete with megabenthic specimens.
  
  
  RESULTS
  Here we use a combination of the standard M1M6 and I3M11 partitions of the COI fragment, partial rDNA 28S sequences and morphology to delineate small encrusting Plocamionida species. In total, 46 specimens were retrieved from seven shallow to deep-water coral locations, crossing 3,000 km along the European margins. Our work provides evidence that the Plocamionida ambigua f. tylotata and f. grandichelata can be considered valid species, whereas Plocamionida ambigua f. tornata corresponds to the species P. ambigua. Within the monophyletic group of Plocamionida, P. microcionides is shown as really divergent from the other taxa, and four putative new Plocamionida species are suggested.
  
  
  CONCLUSIONS
  This study shows that the use of molecular and morphological information in an integrative approach is a powerful tool for the identification of sponge species, and suggests that an under-estimated biodiversity of sponges occurs in cold-water coral reefs.
authors.affiliation: Marine Biology Section, Biology Department, Ghent University, Ghent, Belgium. julie.reveillaud@ugent.be
authors.forename: Julie
authors.initials: J
authors.lastname: Reveillaud
authors.forename: Rob
authors.initials: R
authors.lastname: van Soest
authors.forename: Sofie
authors.initials: S
authors.lastname: Derycke
authors.forename: Bernard
authors.initials: B
authors.lastname: Picton
authors.forename: Annelien
authors.initials: A
authors.lastname: Rigaux
authors.forename: Ann
authors.initials: A
authors.lastname: Vanreusel
mesh_terms: D000818:Animals; D044822:Biodiversity; D057894:Coral Reefs; D004272:DNA, Mitochondrial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D010802:Phylogeny; D011161:Porifera / Q000145:classification* / Q000235:genetics / Q000254:growth & development
chemical_list: D004272:DNA, Mitochondrial; D004275:DNA, Ribosomal; D003576:Electron Transport Complex IV