Microstructural Features of Teleost Otoliths

Abstract

We have examined the macro- and microstructural features of teleost otoliths using light and scanning electron microscopy. There is a wide range in otolith morphology within the teleosts with little apparent relationship between otolith size and structure and the biology of the species. Once otolith formation began, the microstructural features, which include the crystals, organic matrix, incremental zone and the associated discontinuous zone of sagittal otoliths, were similar. Increments were dbserved to begin formation at different times in different species. Examples of such features from freshwater, brackish water, and marine species; active and passive species; egg layers and live bearers; and benthic and pelagic species are shown. The otolith appears to be a permanent physiological record of the fish and applications of the information it contains will be discussed.