The Prismatic Layer of Pinna: A Showcase of Methodological Problems and Preconceived Hypotheses

Abstract

Abstract:The prismatic layer of Pinna (Mollusca) is one of the most studied models for the understanding of the biomineralization mechanisms, but our knowledge of the organic components of this layer is limited to the proteins of the soluble organic matrices. The interplay of the mineral and organic matrices is studied using scanning electron and atomic force microscopy, infra-red spectrometry, thermogravimetric analyses, aminoacids analyses, thin layer chromatography (TLC), X-ray fluorescence, X-ray Absorption near Edge Structure (XANES) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). Proteins, polysaccharides and lipids are detected within the prisms and their envelopes. The role of the technical choices to study calcareous biominerals is evidenced, showing that a single analysis is not enough to decipher complex biominerals.

Insights into architecture, growth dynamics, and biomineralization from pulsed Sr-labelled <i>Katelysia rhytiphora</i> shells (Mollusca, Bivalvia)

“…S13) and the constant thickness of the Sr-labelled shell demonstrates that growth rates, measured perpendicular to the growth front, are homogeneous across this area. This undulation is not observed in other prismatic ultrastructures (simple prismatic ultrastructure: Dauphin et al, 2018) and the underlying reasons for this are yet unknown.…”

“…Calculations were made with the Hill averaging scheme (colour scale on the right). (d) The Young's modulus for a aragonite single crystal is calculated with the Voigt-Reuss-Hill averaging scheme and is based on the elastic constants published in De Villiers (1971). We used the aragonite single crystal elastic properties of Liu et al (2005) and the EBSD data collected from K. rhytiphora from this study as inputs (GL -local growth line, DOG -local direction of growth.…”

Ribs of Pinna nobilis shell induce unexpected microstructural changes that provide unique mechanical properties

“…The CCP layers of bivalves have been widely studied 17,[22][23][24][25][26][27] . However, their mechanical properties have received little attention compared to nacre [28][29][30][31] and crossed-lamellar microstructures 32,33 .…”

Prism substructures in the shell of Pinna nobilis (Linnaeus, 1758), Mollusca – Evidence for a three-dimensional pulsed-growth model

“…Phase contrast imaging ( Figure 3 e) shows individual grains with an irregular round-shaped morphology without any cleavage plans. Grains 50–100 nm in diameter are coated by a thin cortex that strongly interacts with the AFM tip, at the difference of the mineral particles ( Dauphin et al., 2018 ).…”