STUDIES ON THE MICROSTRUCTURE OF OTOLITHS AND THE ESTIMATION OF THE DURATION OF LARVAL STAGE IN GLASS EEL (Anguilla anguilla) IN MAROCCAN COASTAL WATERS

Abstract

Dimensional and microstructural analyses on the otoliths of glass eels (Anguilla anguilla) of two populations, one from the Atlantic coast (Sebou Estuary) and the other from the Mediterranean coast (Mouloya Estuary), were made using optical and scanning electron microscopy. A comparative study revealed that Atlantic and Mediterranean glass eel showed approximately one month difference in their migration periods. This difference was marked on the growth area of the otoliths, justifying the different migratory routes undertaken by the two populations, starting from the Sargasso Sea up to the continental waters.