Diet of subadult Australian salmon, Arripis truttaceus, in Western Port, Victoria

Abstract

Stomach contents from 285 pelagically feeding Australian salmon (Arripis truttaceus) caught in Western Port, Victoria, between May 1992 and June 1993 were examined. Stomach contents consisted of three species of clupeoid fishes. These were, in order of importance, anchovy (Engraulis australis), pilchard (Sardinops neoplchardus) and sandy sprat (Hyperlophus vittatus). The diet of A. truttaceus varied on a seasonal basis, both in terms of prey species composition and prey age (juvenile or adult). Adult anchovy were the dominant food item between October and January. In May 1992 and in February and March 1993, juvenile clupeoids dominated gut samples, with most of these being anchovy and pilchard. Sandy sprat comprised a significant component of gut samples in May 1992 and June 1993. Two size groups of salmon were temporarily resident in Western Port. The largest salmon were caught in October and November, and these were replaced by a smaller size group that dominated catches between December and June. The arrival of A. truttaceus subadults in Western Port in spring and their gradual departure from the bay in the late autumn and winter appears to be closely tied to the seasonal inshore/offshore migrations of prey species.