https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31429 Chelidonichthys kumu, Grooved Gurnard Lepidotrigla modesta, and Roundsnout Gurnard Lepidotrigla mulhalli), were examined for the presence of such dietary niches. The species are either fishery-important (Red Gurnard) or provide prey (Grooved Gurnard and Roundsnout Gurnard) for fishery-important species (e.g., Platycephalidae and Zeidae). Based on stomach content analyses, all three gurnards were shown to be bottom-feeding carnivores that consumed mainly benthic crustaceans, particularly decapods and amphipods, with teleosts also being important in the diets of only the larger Red Gurnard. Nonmetric multidimensional scaling ordination and multivariate analyses based on volumetric contributions of different prey taxa to the stomach contents revealed significant differences in dietary composition among all three species, implying a partitioning of food resources. Size-related and temporal changes in dietary composition were each significant among the three gurnards, but there were no interactions between body size and time. Principal components analysis of head and mouth morphology demonstrated that mouth protrusiveness was the dominant morphological difference among species, which may in part account for the niche partitioning observed from the stomach content analysis. Given the important role of gurnards in benthic food webs, these relationships will improve the specification of ecosystem-based fisheries models and their ability to predict the effects of environmental and anthropogenic perturbations.]]> Wed 11 Apr 2018 14:09:53 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33357 Lepidotrigla mulhalli and L. vanessa from south-eastern Australia were analysed using stomach content and stable isotope ratios (δ¹³C and δ¹⁵ N). Both species are bottom-feeding carnivores that consumed mainly benthic crustaceans, but teleosts were also abundant in the diet of larger L. vanessa. Non-metric multidimensional scaling (nMDS) ordination and analysis of similarity (ANOSIM) of dietary data revealed significant inter-specific dietary differences; i.e. food resource partitioning. Carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotope values were similar between L. mulhalli and L. vanessa, however, suggesting similar trophic positioning. Ontogenetic changes in diet composition and stable isotope values were evident. As L. vanessa grew, they preyed upon larger individuals, such as teleosts and caridean shrmips, but no such trend was observed in the diets of L. mulhalli. Adults of both species were significantly enriched in ¹⁵N relative to juvenile conspecifics thus supporting these data. Consequently, in this study, both methodologies, i.e. stomach content and stable isotope analyses, provided evidence of inter- and/or intra-specific dietary segregations and trophic niche partitioning between co-occurring L. mulhalli and L. vanessa off Tasmanian waters.]]> Wed 04 Sep 2019 09:56:13 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:48304 Tue 14 Mar 2023 14:13:46 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35112 Scyliorhinus torazame were studied with the aid of 117 specimens collected from the southern sea of Korea. S. torazame was mainly piscivorous, but also ingested polychaetes and small amounts of benthic crustaceans. This dietary composition led to an estimated trophic level of 3.9 for the species. The diets of S. torazame changed significantly with season, but not length or sex of the sharks. Graphical analysis indicated that S. torazame is a benthic generalist feeder that consumes a variety of prey, but also showed high individual diet specialization.]]> Thu 11 May 2023 10:27:08 AEST ]]>