The Populations of Australian 'Salmon', Arripis trutta (Bloch & Schneider), in Australian Waters

Abstract

In Australian waters the stock of Australian "salmon", a percomorph form, is composed of two clearly defined populations. These populations are referred to as the eastern and western subspecies. The western subspecies is normally the only group found in Western and South Australia, whereas the eastern subspecies is normally the only group found in New South Wales. The distributions of the subspecies overlap in Tasmania and Victoria. The subspecies differ in the number of rakers on the first gill arch; the western subspecies has 25-31 rakers, the eastern subspecies 33-40. The number of gill rakers can be related to the mode of feeding as the predominant food of the western subspecies is the pilchard, Sardinops neopilchardus (Steindachner), while that of the eastern subspecies is the euphausiid, Nyctiphanes australis Sars. Small but significant differences are evident in the number of rays in the dorsal fin, and in the number of scales around the girth.