eCite Digital Repository
Dietary compositions of the sparid Acanthopagrus butcheri in three normally closed and variably hypersaline estuaries differ markedly
Citation
Chuwen, BM and Platell, ME and Potter, IC, Dietary compositions of the sparid Acanthopagrus butcheri in three normally closed and variably hypersaline estuaries differ markedly, Environmental Biology of Fishes, 80, (2007) pp. 363-376. ISSN 0378-1909 (2007) [Refereed Article]
![]() | PDF Not available 361Kb |
Copyright Statement
Copyright © Springer Science+Business Media B.V. 2007 The final publication is available at http://www.springerlink.com
DOI: doi:10.1007/s10641-006-9134-0
Abstract
We have compared the species composition
and diversity of the diets of black
bream, Acanthopagrus butcheri, in three normally
closed estuaries on the central south coast
of Western Australia, which vary markedly in
the extents to which they become hypersaline
during dry periods. Although black bream was
caught seasonally in Stokes Inlet during this
3-year study, it was obtained from the
Hamersley and Culham inlets only during the
earlier seasons because salinities in those two
estuaries subsequently rose to levels that caused
massive mortalities of this sparid. Although a
wide range of taxa, including macrophytes,
polychaetes, molluscs, crustaceans, insects and
teleosts, were ingested by A. butcheri in each
estuary, the frequencies of ingestion and volumetric
dietary contributions of these taxa varied
greatly among the fish in these three estuaries.
Thus, for example, in comparison with other
estuaries, relatively greater contributions were
made to the diet by polychaetes and crustaceans
in Stokes Inlet, by macrophytes in Hamersley
Inlet, and by insects (mainly chironomid larvae)
in Culham Inlet. The relatively greater contribution
of teleosts to the diets of black bream in
the Hamersley and Culham inlets than in Stokes
Inlet, and also differences in the main teleost
species ingested in the first two estuaries, are
consistent with differences in the densities of
fish overall and of the main fish species in those
estuaries. The diversity of the diet was far
greater in Stokes Inlet than in the other two far
more variably saline estuaries, presumably
reflecting a greater diversity of food. The dietary
compositions of black bream in upstream pools
in the tributary of Culham Inlet, which offer
refuge when salinities increase markedly in the
main body of the estuary, differ from those in
those downstream regions, further emphasising
the opportunistic nature of the feeding behaviour
of black bream. The dietary compositions
of black bream underwent size-related changes,
but the taxa contributing most to those changes
varied greatly among estuaries. Size-related
changes would be particularly beneficial in
reducing intraspecific competition for food in
the two estuaries that vary greatly in salinity
and would thus be likely to contain a less
diverse range of prey.
Item Details
Item Type: | Refereed Article |
---|---|
Keywords: | Sparidae Diets Composition Diversity Opportunism Normally closed estuaries |
Research Division: | Agricultural, Veterinary and Food Sciences |
Research Group: | Fisheries sciences |
Research Field: | Aquaculture |
Objective Division: | Animal Production and Animal Primary Products |
Objective Group: | Fisheries - wild caught |
Objective Field: | Fisheries - recreational freshwater |
UTAS Author: | Chuwen, BM (Dr Ben Chuwen) |
ID Code: | 71847 |
Year Published: | 2007 |
Web of Science® Times Cited: | 22 |
Deposited By: | Sustainable Marine Research Collaboration |
Deposited On: | 2011-08-10 |
Last Modified: | 2011-11-04 |
Downloads: | 2 View Download Statistics |
Repository Staff Only: item control page