Nanostructures de la nacre des tests de céphalopodes actuels

  title={Nanostructures de la nacre des tests de c{\'e}phalopodes actuels},
  author={Yannicke Dauphin},
The structures of the two types of nacreous layers previously described in cephalopod shells were studied with AFM (atomic force microscopy). The comparison of these results with those of SEM (scanning electron microscopy) and TEM (transmission electron microscopy) studies shows similarities and differences. Nacreous lamellae are composed of fibrillar crystallites, but these crystallites may not be composed of smaller elongated and parallel crystallites. Fibrillar crystallites seem to be… Expand
Structure and composition of the septal nacreous layer of Nautilus macromphalus L. (Mollusca, Cephalopoda).
A set of combined analytical data shows that the organic matrices extracted from the nacreous layer are glycoproteins, and it is possible that the observed differences in the structure and composition of the n acreous layers of the outer wall and septa of the Nautilus shell have a dual origin: evolution and functional adaptation. Expand
Octocoral sclerite ultrastructures and experimental approach to underlying biomineralisation principles
Skeletal biominerals often show complex morphologies and ultrastructures that are important for their mechanical function. The production of these biomineral structures requires exact control overExpand
Structure and composition of calcareous sponge spicules: a review and comparison to structurally related biominerals.
Despite the variety of poriferan spicule mineralogy and the distant phylogenetic relationship between sponges and echinoderms, all of these biominerals share similarities regarding their nano-scale construction. Expand
Narrowly Distributed Crystal Orientation in Biomineral Vaterite
Biominerals formed by animals provide skeletal support and many other functions. They were previously shown to grow by aggregation of amorphous nanoparticles but never to grow ion-by-ion fromExpand
Mesoscale twinning and crystallographic registers in biominerals
Abstract Mesocrystals attract increasing interest in the fields of physics, chemistry, materials, and Earth sciences. Yet, structural properties of this new class of solid materials are not fullyExpand
Crystallographic control on the substructure of nacre tablets.
The study shows that the growth dynamics of nacre tablets (and bioaragonite in general) results from the interaction at two different and mutually related levels: tablets and nanogranules. Expand
Crystallographic orientation inhomogeneity and crystal splitting in biogenic calcite
Orientational gradients and splitting processes are described in biocrystals for the first time and are undoubtedly related to the high content of intracrystalline organic molecules, although the way in which these act to induce the observed crystalline patterns is a matter of future research. Expand
Crystalline structure, orientation and nucleation of the nacreous tablets in the cephalopod Nautilus
The nacreous tablets in the Nautilus shell have similar crystalline structure as the tablets in the gastropod Gibbula shell. Etching with Mutvei’s solution reveals that each tablet is composed ofExpand
A high resolution analysis of the structure and chemical composition of the calcareous corpuscles from Mesocestoides corti.
The calcareous corpuscles are spheroid or ovoid layered concretions formed by topographically homogeneous but compositionally heterogeneous layers, suggesting a cyclic process of biomineralization. Expand
Nacre ultrastructure: amorphous precursors, aggregation and crystallization
Abstract Biominerals are organo-mineral composites synthetized by organisms. A composite is defined as the material that results from the combination of two or more different and structurallyExpand


Ultrastructural Characteristics of the Nacre in Some Gastropods
The nacreous layer in Gibbula, Calliostoma, Trochus and Haliotis is described on the basis of scanning electron microscopic studies and the mechanical properties of the nacre, and the effects of the interlamellar conchiolin membranes upon the nucleation of the tablets are discussed. Expand
Macromolecules in mollusc shells and their functions in biomineralization
Mollusc shells are used as a model for studying ‘organic-matrix -mediated’ biomineralization, in which crystals are nucleated and grow in a pre-formed structural framework composed of proteins andExpand
  • C. Grégoire
  • Biology, Medicine
  • The Journal of biophysical and biochemical cytology
  • 1957
The present results support former conclusions with regard to the existence of taxonomic differences between Cephalopods, Gastropods, and Pelecypods in the morphological organization of the organic phase within mother-of-pearl. Expand
The nacreous layer in Mytilus, Nucula, and Unio (Bivalvia). Crystalline composition and nucleation of nacreous tablets.
  • H. Mutvei
  • Chemistry, Biology
  • Calcified tissue research
  • 1977
Etching with the glutaraldehyde-acetic acid solution reveals that the nacreous tablets in Mytilus, Nucula, and Unio are composed of four crystal individuals which occur in two structurally differentExpand
Composition chimique de la fraction “nacroine” de la conchioline de nacre de Nautilus pompilius lamarck
It appears that chitin is the most stable component of the nacroin, and consequently of the conchiolin of Nautilus mother-of-pearl. Expand
  • N. Watabe, K. Wilbur
  • Chemistry, Medicine
  • The Journal of biophysical and biochemical cytology
  • 1961
Details of crystal growth in the calcitostracum of Crassostrea virginica have been studied with the purpose of analyzing the formation of the overlapping rows of oriented tabular crystalsExpand
Diagenese comparee des phases minerales et organiques solubles dans les tests aragonitiques de nautiles et d9ammonites
The compositions of both organic and mineral parts of shells of Nautilus macromphalus, a Cenozoic nautiloid and Jurassic ammonites are compared. The microstructures of the fossil shells show minorExpand
Using Plasma-Etching and Proteolytic Enzymes in Studies of Molluscan Shell Ultrastructure
As in all mineralized tissues, the mineral components of the molluscan shell are associated with complex organic matrices. In order to study shell ultrastructure with the SEM the shell must first beExpand
Spiral Growth of Nacre
INTERESTING spiral patterns (Fig. 1) were found on the growing inner surface of nacre when the fresh inner surface of pelecypod shells was observed under a microscope using a vertical illuminator.Expand