Myzostomida: A review of the phylogeny and ultrastructure

  • Igor Eeckhaut
  • Deéborah Lanterbecq
Part of the Developments in Hydrobiology book series (DIHY, volume 179)


Myzostomids are minute, soft-bodied, marine worms associated with echinoderms since the Carboniferous. Due to their long history as host-specific symbionts, they have acquired a highly derived body plan that obscures their phylogenetic affinities to other metazoans. Because certain organs are serially arranged a closer relationship between polychaetes and myzostomids has repeatedly been discussion. We presented here a review on the ultrastructure of myzostomids with the most recent analyses that concern their phylogenetic position. The ultrastructure of the integument, digestive system, excretory system and nervous system are summarized. Unpublished information on the gametogenesis and reproductive systems of myzostomids are also exposed with a view on their reproductive process.

Key words

Myzostomida Annelida phylogeny ultrastructure 


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Copyright information

© Springer 2005

Authors and Affiliations

  1. 1.Marine Biology Laboratory, Natural Sciences BuildingUniversity of Mons-HainautMonsBelgium

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