Ecology of juvenile King George whiting Sillaginodes punctatus (Cuvier & Valenciennes) (Pisces: Perciformes) in Western Port, Victoria

Abstract

The growth rates, feeding and habitat preferences of juvenile S. punctatus over seagrass flats (Zostera muelleri and Heterozostera tasmanica) in Western Port, Victoria, were studied between June 1974 and January 1976. 0+ and 1 + age group fish were always present in the study area, whilst 2+ age group fish were present in small numbers from June 1974 to February 1975. Two equations describing the increase in weight of fish less than and greater than 7 months of age are given.

The initial diet of the 0+ age group fish is harpacticoid copepods and amphipods, and the ghost prawn, Callianassa australiensis, is the major prey item of the older fish. Young 0+ age group fish were found to inhabit heavily grassed areas of the seagrass flats, whilst older fish preferred lightly grassed or bare, muddy areas. Adults of S. punctatus spawn in winter (May to July), probably in localized, shallow, subtidal areas of the bay. Post-larvae were first captured in the seagrass beds in September. The importance of these areas as nursery grounds for juveniles of S. punctatus is stressed.