Abstract

• Based on the external morphologies of fish, a total of 20 species of estuarine fishes selected from the mouth of Thanlwin River were identified and the sagittae otoliths were taken out from fish. The result of this study showed that otoliths of pelagic fishes compared with otoliths of demersal fishes are smaller and thinner. Furthermore otoliths of different species can have similarities in appearance but they have enough differences to be distinguished from each other. In this study, different shapes of otoliths are recorded in the fishes caught from the river mouth area of Thanlwin. These included elliptic, square, discoid, rectangle, lanceolate, triangle, pistalform and spindle shapes.