Teleost fish have the capacity to record in their otoliths, calcareous concretions located in the inner ear, the principal events (environmental and physiological) which punctuate their life. Otolith is made of CaC03 deposits on a protein matrix according to a circadian rhythm. Due to the quasi irreversibility of this process, otoliths can be compared to biological archives largely used to apprehend the fish ecology. The otolith bathes in the endolymph, a medium in which all the precursors of otolith formation forward. The endolymph chemical analysis revealed a heterogeneity of its principal components (proteins, total C02 and total Ca) which origin lies in the non uniform spatial distribution of the ionocytes in the saccular epithelium. Thus, in... |