Evidence of low molecular weight components in the organic matrix of the reef building coral, Stylophora pistillata.

Biominerals contain both inorganic and organic components. Organic components are collectively termed the organic matrix, and this matrix has been reported to play a crucial role in mineralization. Several matrix proteins have been characterized in vertebrates, but only a few in invertebrates, primarily in Molluscs and Echinoderms.

Characterization and variations of organic parameters in teleost fish endolymph during day-night cycle, starvation and stress conditions.

The aim of the present work was to examine the modifications of the organic composition of fish endolymph under environmental conditions (day-night cycle, starvation and Cl2-stress) known to modify otolith growth. Endolymph electrophoretic patterns were compared. An antibody raised against the trout otolith organic matrix allowed examining the variations of organic matrix precursors in the endolymph under the above conditions.

Composition of biomineral organic matrices with special emphasis on turbot (Psetta maxima) otolith and endolymph.

The soluble organic matrix (OM) of various biominerals (red coral skeleton, oyster shell, sea urchin test, turbot otolith, chicken eggshell) was extracted after demineralization with acetic acid. The protein content of the OM varies strongly from 0.02 to 1.

Daily variations of endolymph composition: relationship with the otolith calcification process in trout.

Ionic and organic parameters of the otolith calcification process in the trout Oncorhynchus mykiss were analysed in plasma and endolymph over the day:night cycle. Plasma pH remained constant and total CO(2) concentration was significantly lower (by 21%) during the day than at night. Calcifying parameters (total CO(2), total calcium concentration) were measured in the proximal and distal endolymphs and were unchanged in the latter during the day:night cycle, but fluctuated in the former.