Structure of the calcitic megaprisms is studied with SEM in the outer shell layer of two archaeogastropod species: Haliotis rufescens Swainson, from the Pacific at San Francisco, and Haliotis tuberculata L., from the Atlantic, Dinard, France. In H. rufescens where the calcitic megaprisms have a regular size, shape and orientation, the prisms are traversed by horizontal organic intracrystalline sheets. These sheets are regularly spaced (about 1 micron apart) and have a parallel fibrous structure. The occurrence of well defined intracrystalline sheets in the prismatic structures has not been reported previously. In H. tuberculata where the calcitic megaprisms occur together with aragonitic granules, and are precipitated at irregular intervals, the prisms have a highly varying size, shape and orientation. The intracrystalline organic matrix seems to form also here horizontal sheets but these are fragile and composed of very thin fibres with reticulate arrangement. Consequently, there exists a close correlation between the organization of the calcitic megaprisms and the intracrystalline organic matrix.

Extremely thin, horizontal, organic sheets are described in the semi-prismatic shell layer in the cephalopod Nautilus pompilius. The spacing of these sheets is similar to that of the interlamellar organic sheets in the adjacent nacreous layer. The following structural changes take place when the semi-prismatic layer is transformed into the nacreous layer: (1) the acicular crystallites acquire a strictly vertical orientation and form nacreous tablets which become twinned, and (2) the simple, horizontal, soluble organic sheets increase in thickness, become three-layered and partially insoluble.


Growth Surface Shell Layer Nacreous Layer Proteolytic Enzyme Trypsin Soluble Organic Fraction 
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  1. BANDEL, K., 1977. Ubergänge von der Perlmutter-Schicht zu prismatischen Schichttypen bei Mollusken. Biomineralization, 9: 28–47.Google Scholar
  2. BEVELANDER, G. and NAKAHARA, H., 1980. Compartment and envelope formation in the process of biological mineralization. In The mechanism of biomineralization in animals and plants (ed. M. Omori and N. Watabe ), pp. 19–27. Tokai Univ. Press.Google Scholar
  3. CRENSHAW, M.A., 1982. Mechanism of normal biological mineralization and demineralization. Dahlem Konferenzen 1982 (ed. G.H. Nancollas), pp. 243–257. Berlin, Heidelberg, New York: Springer-VerlagGoogle Scholar
  4. CUIF, J.-P., DENIS, A. and GASPARD, D., 1981. Recherche d’une méthode d’analyse ultrastructurale des tests carbonatés d’Invertébrés. Bull. Soc. geol. France, 23: 525–534.Google Scholar
  5. ERBEN, H.K., 1971. Anorganische und organische Schalenkomponenten bei Cittarium pica (L.) ( Archaeogastropoda ). Biomineralization, 3: 51–64.Google Scholar
  6. GRÉGOIRE, C., 1962. On submicroscopic structure of Nautilus shell. Bull. Inst. Roy. Soc. Natur. Belgique, 38: 1–71.Google Scholar
  7. KULICKI, C. and MUTVEI, H., 1982. Ultrastructure of the siphonal tube in Quenstedtoceras (Ammonitina). Stockholm Contr. Geol., 37: 129–138.Google Scholar
  8. MUTVEI, H., 1964. On the shells of Nautilus and Spirula with notes on the shell secretion in non-cephalopod molluscs. Arkiv fr Zoologi, 16: 221–278.Google Scholar
  9. MUTVEI, H., 1969. On the micro-and ultrastructure of the conchiolin in the nacreous layer of some recent and fossil molluscs. Stockholm Contr. Geol., 22: 1–17.Google Scholar
  10. MUTVEI, H., 1972a. Ultrastructural relationships between the prismatic and nacreous layers in Nautilus ( Cephalopoda ). Biomineralization, 4, 81–86.Google Scholar
  11. MUTVEI, H., 1972b. Ultrastructural studies on cephalopod shells. Bull. Geol. Instn. Univ. Uppsala N.S. 3: 237–261.Google Scholar
  12. MUTVEI, H., DAUPHIN, Y., and CUIF, J.-P., 1985. Observations sur l’organisation de la couche externe du test des Haliotis (Gastropoda): un cas exceptionnel de variabilité mineralogique et microstructurale. Bull. Mus. Nat. Hist., Paris, 4e sér., 7: 73–91.Google Scholar
  13. NAKAHARA, H., 1983. Calcification of gastropod nacre. In Biomineralization and biological metal accumulation (ed. P. Westbroek and E.W. DeJong ), pp. 225–230. D. Reidel Publ. Co.CrossRefGoogle Scholar
  14. NAKAHARA, H., BEVELANDER, G. and KAKEI, M., 1982. Electron microscopic and amino acid studies on the outer and inner shell layers of Haliotis rufescens. Venus (Jap. J. Malac. ), 41: 33–46.Google Scholar
  15. SUZUKI, S. and UOZUMI, S., 1981. Organic components of prismatic layers in molluscan shells. J. Fac. Sci., Hokkaido Univ., Ser. 4, 20: 7–20.Google Scholar
  16. WATABE, N. and DUNKELBERGER, D.G., 1979. Ultrastructural studies on calcification in various organisms. Scan. Elec. Microsc. 1979 /11: 403–416.Google Scholar
  17. WISE, JR., S.W. and HAY, W.W., 1968. Scanning electron microscopy of molluscan shell ultrastructures. Trans. Amer. Microsc. Soc., 87: 419.CrossRefGoogle Scholar

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© Springer Science+Business Media New York 1989

Authors and Affiliations

  • Harry Mutvei
    • 1
  1. 1.Department of PalaeozoologySwedish Museum of Natural HistoryStockholmSweden

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