Thesis
Dietary composition of benthic predatory teleosts in Cockburn Sound, Western Australia
Masters by Research, Murdoch University
2023
Abstract
The prey consumed by a species reflects its morphology and the partitioning of resources among conspecifics and co-occurring species. This study determined the dietary composition and morphological traits of three benthic predatory fish species, i.e., the platycephalids Inegocia japonica and Onigocia spinosa (tropical species whose distributions have shifted poleward) and the callionymid Pseudocalliurichthys goodladi in Cockburn Sound, a marine embayment in temperate Western Australia. The diet of these species was also compared to four previously studied platycephalids. Multivariate analyses showed that the diet of all three species differed with I. japonica consuming mainly teleosts, carideans and alpheid shrimp, O. spinosa carideans and amphipods and P. goodladi molluscs, polychaetes, and foraminifera. Seasonal changes in diet were detected in all species, with spatial and ontogenetic differences also occurring in I. japonica and P. goodladi. The was a significant relationship between morphological traits and dietary composition, with differences in oral gape and speed of locomotion influencing the prey these species could capture and ingest. For example, P. goodladi was the most morphologically distinct, with its longer mouth protrusion, small oral gape, and low initial strike acceleration. Thus, this species was unable to capture more mobile crustaceans and teleosts, but its longer mouth protrusion and small oral gape increased its efficiency to predate on relatively sessile benthic invertebrates. Previously published data on other resident platycephalids indicates that Platycephalus speculator and Platycephalus westraliae, Leviprora inops and Platycephalus grandispinis all consumed considerable amounts of large crustaceans with the latter species also ingesting large volumes of teleosts. Thus, the diet of the recently arrived I. japonica and O. spinosa does not overlap substantially with the existing platycephalids indicating that members of this family partition dietary resources in Cockburn Sound.
Details
- Title
- Dietary composition of benthic predatory teleosts in Cockburn Sound, Western Australia
- Authors/Creators
- Mitchell Haywood
- Contributors
- James Tweedley (Supervisor) - Murdoch University, Centre for Sustainable Aquatic EcosystemsNeil Loneragan (Supervisor) - Murdoch University, Centre for Sustainable Aquatic EcosystemsGlenn Hyndes (Supervisor)
- Awarding Institution
- Murdoch University; Masters by Research
- Identifiers
- 991005564668707891
- Murdoch Affiliation
- Centre for Sustainable Aquatic Ecosystems
- Resource Type
- Thesis
- Note
- Accelerated Research Masters with Training at Murdoch University
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