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.

  • Letter
  • Published:

Architecture and material properties of diatom shells provide effective mechanical protection

Abstract

Diatoms are the major contributors to phytoplankton blooms in lakes and in the sea and hence are central in aquatic ecosystems and the global carbon cycle1. All free-living diatoms differ from other phytoplankton groups in having silicified cell walls in the form of two ‘shells’ (the frustule) of manifold shape and intricate architecture2 whose function and role, if any, in contributing to the evolutionary success of diatoms is under debate3,4,5. We explored the defence potential of the frustules as armour against predators by measuring their strength. Real and virtual loading tests (using calibrated glass microneedles and finite element analysis) were performed on centric and pennate diatom cells. Here we show that the frustules are remarkably strong by virtue of their architecture and the material properties of the diatom silica. We conclude that diatom frustules have evolved as mechanical protection for the cells because exceptional force is required to break them. The evolutionary arms race between diatoms and their specialized predators will have had considerable influence in structuring pelagic food webs and biogeochemical cycles.

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

Access options

Buy this article

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

Figure 1: Glass needle tests: Live single cells of T. punctigera (ac) and F. kerguelensis (df), in chains (e, f).
Figure 2: Finite element calculations of F. kerguelensis frustules.
Figure 3: Properties of an isolated girdle band.

Similar content being viewed by others

References

  1. Smetacek, V. Diatoms and the ocean carbon cycle. Protist 150, 25–32 (1999)

    Article  CAS  Google Scholar 

  2. Round, F. E., Crawford, R. M. & Mann, D. G. The Diatoms: Biology and Morphology of the Genera (Cambridge Univ. Press, Cambridge, UK, 1990)

    Google Scholar 

  3. Tilman, D. & Kilham, P.. Sinking in freshwater phytoplankton: Some ecological implications of cell nutrient status and physical mixing processes. Limnol. Oceanogr. 21, 409–417 (1976)

    Article  ADS  Google Scholar 

  4. Hale, M. S. & Mitchell, J. G. Functional morphology of diatom frustule microstructures: hydrodynamic control of Brownian particle diffusion and advection. Aquat. Microb. Ecol. 24, 287–295 (2001)

    Article  Google Scholar 

  5. Milligan, A. J. & Morel, F. M. M. A proton buffering role for silica in diatoms. Science 297, 1848–1850 (2002)

    Article  ADS  CAS  Google Scholar 

  6. Gersonde, R. & Harwood, D. M. Lower Cretaceous diatoms from ODP Leg 113 site 693 (Weddell Sea). Part 1: vegetative cells. Proc. ODP Sci. Res. 113, 365–402 (1990)

    Google Scholar 

  7. Burkhardt, B. & Bach, K. Diatoms 1—Shells in Nature and Technics (Cramer, Braunschweig, 1984)

    Google Scholar 

  8. Ehrenberg, C. G. Die Infusionsthierchen als vollkommene Organismen. Ein Blick in das tiefere organische Leben der Natur (Leopold Voss, Leipzig, 1838)

    Google Scholar 

  9. Smetacek, V. A watery arms race. Nature 411, 745 (2001)

    Article  ADS  CAS  Google Scholar 

  10. Round, F. E. The problem of reduction of cell size during diatom cell division. Nova Hedwigia 23, 291–303 (1972)

    Google Scholar 

  11. Verity, P. G. & Smetacek, V. Organism life cycles, predation, and the structure of marine pelagic ecosystems. Mar. Ecol. Prog. Ser. 130, 277–293 (1996)

    Article  ADS  Google Scholar 

  12. Ashman, R. B., Cowin, S. C., Van Buskirk, W. C. & Rice, J. C. A continuous wave technique for the measurement of the elastic properties of cortical bone. J. Biomech. 17, 349–361 (1984)

    Article  CAS  Google Scholar 

  13. Willems, G., Lambrechts, P., Braem, M., Celis, J. P. & Vanherle, G. A classification of dental composites according to their morphological and mechanical characteristics. Dent. Mater. 8, 310–319 (1992)

    Article  CAS  Google Scholar 

  14. Kröger, N., Deutzmann, R. & Sumper, M. Polycationic peptides from diatom biosilica that direct silica nanosphere formation. Science 286, 1129–1132 (1999)

    Article  Google Scholar 

  15. Fortin, D. & Vargas, M. A. The spectrum of composites: new techniques and materials. J. Am. Dental Assoc. 131, 26–30 (2000)

    Article  Google Scholar 

  16. Crawford, S. A., Higgins, M. J., Mulvaney, P. & Wetherbee, R. Nanostructure of the diatom frustule as revealed by atomic force and scanning electron microscopy. J. Phycol. 37, 543–554 (2001)

    Article  Google Scholar 

  17. Thompson, J. B. et al. Bone indentation recovery time correlates with bond reforming time. Nature 414, 773–776 (2001)

    Article  ADS  CAS  Google Scholar 

  18. Sullivan, B. K., Miller, C. B., Peterson, W. T. & Soeldner, A. H. A scanning electron microscopy study of the mandibular morphology of boreal copepods. Mar. Biol. 30, 175–182 (1975)

    Article  Google Scholar 

  19. Suh, H. L. The gastric mill of euphausiid crustaceans: a comparison of eleven species. Hydrobiologia 321, 235–244 (1996)

    Article  Google Scholar 

  20. Fowler, S. W. & Fisher, N. S. Viability of marine phytoplankton in zooplankton fecal pellets. Deep-Sea Res. 30, 963–969 (1983)

    Article  ADS  Google Scholar 

  21. Weis-Fogh, T. & Alexander, R. M. in Scale Effects in Animal Locomotion (ed. Pedley, T. J.) 511–525 (Academic, London, 1977)

    Google Scholar 

  22. Atkinson, A. Omnivory and feeding selectivity in five copepod species during spring in the Bellingshausen Sea, Antarctica. ICES J. Mar. Sci. 52, 385–396 (1995)

    Article  Google Scholar 

  23. Smetacek, V. The annual cycle of protozooplankton in the Kiel Bight. Mar. Biol. 63, 1–11 (1981)

    Article  Google Scholar 

  24. Jacobson, D. M. A brief history of dinoflagellate feeding research. J. Eukaryot. Microbiol. 46, 376–381 (1999)

    Article  Google Scholar 

  25. Haeckel, E. Kunstformen der Natur (Bibliographisches Institut, Leipzig/Vienna, 1904)

    Google Scholar 

  26. Cifuentes, A. O. & Kalbag, A. A performance study of tetrahedral and hexahedral elements in 3-D finite element structural analysis. Finite Elements Anal. Des. 12, 313–318 (1992)

    Article  Google Scholar 

  27. Steucek, G. & Schmid, A.-M. M. in Beiträge zum 1. internationalen Symposion des Sonderforschungsbereiches 230 Natürliche Konstruktionen, Leichtbau in Architektur und Natur Teil 2 194–203 (Sprint-Druck GmbH, Stuttgart, 1989)

Download references

Acknowledgements

We thank F. Hinz and R. Crawford for the SEM image of F. kerguelensis. U. Riebesell, D. Wolf-Gladrow, U. Bathmann and R. Crawford provided comments.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Christian E. Hamm.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Hamm, C., Merkel, R., Springer, O. et al. Architecture and material properties of diatom shells provide effective mechanical protection. Nature 421, 841–843 (2003). https://doi.org/10.1038/nature01416

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature01416

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