Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Cycliophora is a new phylum with affinities to Entoprocta and Ectoprocta

Abstract

THE mouthparts of the Norway lobster Nephrops are colonized by an acoelomate metazoan, Symbion pandora gen. et sp. nov. Sessile stages continually produce inner buds replacing feeding structures. They also produce one of three motile stages: (1) larvae containing new feeding stages, (2) dwarf males, which settle on feeding stages, or (3) females, which settle onto lobster mouthparts, and eventually degenerate, giving rise to dispersive larvae. All motile stages are short-lived, and do not feed. The structure and function of the cilia suggest a phylogenetic position in Protostomia, while some aspects of inner budding and brooding of larvae are similar to those of Entoprocta and Ectoprocta. The dispersive larva possesses a mesodermal supporting chordoid structure, otherwise absent in protostomian larvae. We believe that all the above features of this previously undescribed species warrant the recognition of a new phylum with affinities to Ectoprocta and Entoprocta.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Similar content being viewed by others

References

  1. Nielsen, C. Acta zool. 68, 205–262 (1987).

    Article  Google Scholar 

  2. Strathmann, R. R., Jahn, T. L. & Fonseca, J. R. C. Biol. Bull. 142, 505–519 (1972).

    Article  Google Scholar 

  3. Nielsen, C. Animal Evolution (Oxford Univ. Press, Oxford, 1995).

    Google Scholar 

  4. Koehler, J. K. J. Ultrastruct. Res. 12, 113–134 (1965).

    Article  CAS  Google Scholar 

  5. Koehler, J. K. & Birky, C. W. Z. Zellforsch. 70, 303–321 (1966).

    Article  CAS  Google Scholar 

  6. Melone, G. & Ferraguti, M. Acta zool. 75, 81–88 (1994).

    Article  Google Scholar 

  7. Wright, K. A. in Microscopic Anatomy of Invertebrates Vol. 4 (eds Harrison, F. W. & Ruppert, E. E.) 111–195 (Wiley-Liss, New York, 1991).

    Google Scholar 

  8. Ruppert, E. E. in Microscopic Anatomy of Invertebrates Vol. 4 (eds Harrison, F. W. & Ruppert, E. E.) 41–109 (Wiley-Liss, New York, 1991).

    Google Scholar 

  9. Rieger, R. M., Ruppert, E., Rieger, G. E. & Schoepfer-Sterrer, C. Zool. Scripta 3, 219–237 (1974).

    Article  Google Scholar 

  10. Manylov, O. G. Acta zool. 76, 1–6 (1995).

    Article  Google Scholar 

  11. Nielsen, C. Ophelia 9, 209–341 (1971).

    Article  Google Scholar 

  12. Marcus, E. Mosdyr (Bryozóa eller Polyzoa) Danm. Fauna Vol. 46, 1–401 (1940).

    Google Scholar 

  13. Brien, P. Annls Soc. r. zool. Belg. 84, 301–444 (1953).

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Funch, P., Møbjerg Kristensen, R. Cycliophora is a new phylum with affinities to Entoprocta and Ectoprocta. Nature 378, 711–714 (1995). https://doi.org/10.1038/378711a0

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/378711a0

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing