A5079297744- Physiological and biochemical adaptations
- Fish Ecology and Management Studies
- Marine and fisheries research
- Ocean Acidification Effects and Responses
- Aquaculture Nutrition and Growth
- Animal Behavior and Reproduction
- Innovation, Sustainability, Human-Machine Systems
- Reproductive biology and impacts on aquatic species
- High Altitude and Hypoxia
- Species Distribution and Climate Change
- Coral and Marine Ecosystems Studies
Deakin University
2021-2024
Rhodes University
2020-2022
Abstract Climate warming is driving the maximum attainable size of many fish species to decrease, yet mechanisms underlying this ‘shrinking’ phenomenon are not well understood. The gill oxygen limitation (GOL) hypothesis perhaps most prominent mechanistic proposition, asserting that, as grow, two‐dimensional surface area (GSA) progressively fails supply enough support continued growth three‐dimensional body—a process exacerbated by increased metabolism associated with warming. However, these...
The lifetime growth of almost all fishes follows a biphasic relationship - juvenile is rapid and adult subsequently decelerates. For trend that so ubiquitous, there no general agreement as to the underlying mechanisms causing decelerate. Ongoing theories argue slows because either gills fail supply body with surplus oxygen needed for continued somatic gain (i.e. limited), or sexual maturation induces switch in energy allocation towards reproduction away from limited). Here, we empirically...
Fish tend to grow faster as the climate warms but attain a smaller adult body size following an earlier age at sexual maturation. Despite apparent ubiquity of this phenomenon, termed temperature-size rule (TSR), heated scientific debates have revealed poor understanding underlying mechanisms. At centre these are prominent marginally tested hypotheses which implicate some form 'oxygen limitation' proximate cause. Here, we test role oxygen limitation in TSR by rearing juvenile Galaxias...
Quantifying how the heart rate of ectothermic organisms responds to environmental conditions (e.g. water temperature) is important information quantify their sensitivity change. Heart studies have typically been conducted in lab environments where fish are confined. However, commercially available implantable biologgers provide opportunity study free-swimming fish. Our aimed determine applicability an device, used on fusiform-shaped salmonids), for a perciform morphology and anatomy prevent...
Current understanding of behavioural thermoregulation in aquatic ectotherms largely stems from systems such as 'shuttle boxes', which are generally limited their capacity to test large-bodied species. Here, we introduce a controlled system that allows large roam freely tank at sub-optimal temperatures, using thermal refuges increase body temperature optimum desired. Of the 10 coral grouper (Plectropomus leopardus; length ∼400 mm) implanted with loggers, three fish maintained themselves...
Abstract Experimental hyperoxia has been shown to enhance the maximum oxygen uptake capacity of fishes under acute conditions, potentially offering an avenue test prominent physiological hypotheses attempting explain impacts climate warming on fish populations ( e.g. , gill‐oxygen limitation driving declines in size). Such benefits experimental must persist chronic conditions if it is provide a valid manipulation relevant hypotheses, yet long‐term have not examined. Here, authors measured...
Climate change not only drives increases in global mean ocean temperatures, but also the intensity and duration of marine heatwaves (MHWs), with potentially deleterious effects on local fishes. A first step to assess vulnerability fishes MHWs is quantify their upper thermal thresholds contrast these limits against current future temperatures during such heating events. Heart failure considered a primary mechanism governing begins occur at where heart rate fails keep pace dependency reaction...
Despite the importance of juvenile growth to lifetime fitness, high variability exists within many fish species where some individuals grow markedly faster than others. Here, we explored whether social context mediated performance in n = 35 Galaxias maculatus by manipulating environment after identifying different phenotypes. We found that initially fast-growing slowed their rate when pooled with similarly individuals, whereas none slow-growing improved other slow-growers. examined for any...