The genetic mineralogical characteristics of fish otoliths and their environmental typomorphism
Otolith is a typical biomineral carrier growing on insides of fish skull with prominent zoning structure formed by alternating layers of protein and calcium carbonate around the nucleus. The zoning number and the thickness of the rhythmic zone can reflect the age and the growing velocity. The δ18O values of the calcium carbonate are indicators of the temperature of the water where the fish lives. The geometry, color, common and trace elements, oxygen and carbon isotopes of the zones can be employed effectively to classify the species, trace the source, migration habits, nutrition level of the fish and the variation of the ocean environment, in order to predict the environmental variation trend of related waters and make strategic plan for fishery production. Thermoluminescence technique can be taken as a new tool in the investigation of fish otolith to describe the heavy metal pollution of related waters, and the thermoluminescence parameters can be used to deduce the source and manage fishery resources.
Key words: Fish otoliths, age, temperature, species, migration, water environment.