Get access
Advertisement

Feeding ecology of King George whiting Sillaginodes punctatus (Perciformes) recruits in seagrass and unvegetated habitats. Does diet reflect habitat utilization?

Authors

  • G. P. Jenkins,

    Corresponding author
    1. Fisheries Research Branch, Department of Primary Industries, P. O. Box 114, Queenscliff, VIC 3225, Australia
    2. Department of Zoology, University of Melbourne, Parkville, VIC 3010, Australia
      Tel.: +61 3 52580 333; email: gjenkins@unimelb.edu.au
    Search for more papers by this author
  • A. Syme,

    1. Department of Zoology, University of Melbourne, Parkville, VIC 3010, Australia
    Search for more papers by this author
  • P. I. Macreadie

    1. Department of Zoology, University of Melbourne, Parkville, VIC 3010, Australia
    2. School of the Environment, University of Technology, Sydney, NSW 2007, Australia
    Search for more papers by this author

Tel.: +61 3 52580 333; email: gjenkins@unimelb.edu.au

Abstract

This study investigated the feeding ecology of King George whiting Sillaginodes punctatus recruits to determine how diet composition varies between habitat types (seagrass and unvegetated habitats), and between sites separated by distance. Broad-scale sampling of seagrass and unvegetated habitats at nine sites in Port Phillip Bay (Australia) indicated the diet composition varied more by distance into the bay than by habitat. Near the entrance to the bay the diet was dominated by harpacticoids and gammarid amphipods, in the middle reaches of the bay the diet was completely dominated by harpacticoids, while at sites furthest into the bay, mysids and crab zoea were also important. Abundances of prey in guts was significantly higher between 1000 and 2200 hours compared with other times, indicating diurnal feeding. Laboratory determined gut evacuation rate (based on an exponential model) was estimated to be −0·54. Daily rations were highly variable among sites and habitat types. Sillaginodes punctatus recruits consumed much higher quantities of prey on unvegetated habitat than seagrass habitat at some middle reach sites; with prey consumption of harpacticoid copepods on unvegetated habitat approaching 3000 individuals per day at one site. The results of this study provide insight into why habitat associations of S. punctatus recruits within mosaics of seagrass and unvegetated habitat show high spatial variation.

Get access to the full text of this article

Ancillary