Marine Biodiversity

, Volume 39, Issue 1, pp 45–55

Molecular analyses reveal high levels of eukaryotic richness associated with enigmatic deep-sea protists (Komokiacea)


    • Department of Zoology and Animal BiologyUniversity of Geneva
  • A. J. Gooday
    • National Oceanographic Centre, European Way
  • T. Cedhagen
    • Department of Marine EcologyUniversity of Aarhus
  • A. Sabbatini
    • Department of Marine SciencesPolytechnic University of Marche
  • J. Pawlowski
    • Department of Zoology and Animal BiologyUniversity of Geneva
Original Paper

DOI: 10.1007/s12526-009-0006-7

Cite this article as:
Lecroq, B., Gooday, A.J., Cedhagen, T. et al. Mar Biodiv (2009) 39: 45. doi:10.1007/s12526-009-0006-7


Komokiaceans are testate agglutinated protists, extremely diverse and abundant in the deep sea. About 40 species are described and share the same main morphological feature: a test consisting of narrow branching tubules forming a complex system. In some species, the interstices between the tubules are filled by sediment, creating a mudball structure. Because of their unusual and sometimes featureless appearance, komokiaceans were frequently ignored or overlooked until they formal description in 1977. The most recent taxonomy places the Komokiacea within the Foraminifera based on general morphological features. To examine their taxonomic position at the molecular level, we analysed the SSU rDNA sequences of two species, Normanina conferta and Septuma ocotillo, obtained either with specific foraminiferal or universal eukaryotic primers. Many different sequences resulted from this investigation but none of them could clearly be attributed to komokiaceans. Although our study failed to confirm univocally that Komokiacea are foraminiferans, it revealed a huge eukaryotic richness associated with these organisms, comparable with the richness in the overall surrounding sediment. These observations suggest strongly that komokiaceans, and probably many other large testate protists, provide a habitat structure for a large spectrum of eukaryotes, significantly contributing to maintaining the biodiversity of micro- and meiofaunal communities in the deep sea.


Deep-seaEnvironmental sequencesForaminiferaKomokiaceaPhylogenyRibosomal DNA

Supplementary material

12526_2009_6_MOESM1_ESM.doc (111 kb)
ESM Table 1Sampling stations (N North, S South, W West, E East, BC Boxcore, MC Multicore)
12526_2009_6_MOESM2_ESM.doc (294 kb)
ESM Table 2GenBank accession numbers

Copyright information

© Senckenberg, Gesellschaft für Naturforschung and Springer 2009