Abstract--Age compositions and growth rates have been determined for populations of Acanthopagrus butcheri in four estuaries and a saline, coastal lake, all of which differ markedly in their morphological, physicochemical, and biotic characteristics. Because the opaque zones in otoliths were shown to form annually, the number of these zones could be used to age individual fish. However, the otoliths of fish that were more than six years old had to be sectioned in order to ...