In situ distribution and characterization of the organic content of the oyster shell Crassostrea gigas (Mollusca, Bivalvia)

Y. Dauphin (1) , A.D. Ball (2) , H. Castillo-Michel (3) , C. Chevillard (4) , J.P. Cuif (1) , B. Farre (1) , Stéphane Pouvreau (5) , Murielle Salome (3)

1 IDES - Interactions et dynamique des environnements de surface
2 National History Museum
3 ID21
4 SIS2M UMR 3299 - Service Interdisciplinaire sur les Systèmes Moléculaires et les Matériaux (ex SCM)
5 PE2M - Physiologie et Ecophysiologie des Mollusques Marins

Cultivation of commercial oysters is now facing the possible influence of global change in sea water composition, commonly referred to as "ocean acidification". In order to test the potential consequence of the predicted environmental changes, a cultivation experiment was carried out. The left and right valves of the oyster shell Crassostrea gigas differ in their structure; moreover, lenses of non compact layers are irregular. The shell layers of juvenile Crassostrea gigas are studied using a variety of highly spatially-resolved techniques to establish their composition and structure. Our results confirm the presence of three different calcitic structural types. The role of the lenses of chalky layers is not yet deciplered. Despite a common mineralogy, the elemental composition of the layers differs. The sulphur aminoacids and sulphated polysaccharide contents of the intracrystalline and intercrystalline matrices differ, as well as those of the structural types. The possible different sensitivity of these structures to environmental changes is still unknown

Domaines: Sciences de la Terre

Y. Dauphin, A.D. Ball, H. Castillo-Michel, C. Chevillard, J.P. Cuif, et al.. In situ distribution and characterization of the organic content of the oyster shell Crassostrea gigas (Mollusca, Bivalvia). Micron, 2013, 44, pp.373-383. ⟨10.1016/j.micron.2012.09.002⟩. ⟨hal-00733507⟩