Otolith analysis of Trachinotus ovatus (L.) has been investigated to determine its crystal structure and some elemental composition with special reference to age. Results revealed that fish otoliths is composed of the aragonite form. Calcium was the most abundant element and showed different concentrations from one age group to another. Strontium was relatively easy to be incorporated into otolith. Chemical analysis of otolith for strontium-calcium concentrations ratio demonstrated changes in

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... emistry related to temperature. Ash percentage increased with increasing age. However, carbon and nitrogen percentage decreased with increasing age. It was concluded that there is strong relationships between otolith composition and age of fish.