Download or read book Evaluating the Effects of Temperature on the Metabolic Rates of Two Sedentary Marine Fishes the Bluebanded Goby and the Woolly Sculpin written by Racine E. Rangel and published by . This book was released on 2018 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Increasing variation in ocean temperature may affect the metabolism and energetic demands of many species. Understanding such effects is particularly important for sedentary species that cannot make large-scale movements in response to changes in environmental conditions. I examined how metabolic rates responded to temperature in the bluebanded goby (Lythrypnus dalli) and the Woolly Sculpin (Clinocottus analis). Oxygen consumption and metabolic rate increased significantly with temperature for both species, but L. dalli was much more sensitive to the effects of temperature than C. analis (Q 10 values were 5.21 and 3.02, respectively). Thermal fluctuations likely play a significant role in the ecology of these species and continued increases in seawater temperature will either necessitate an increase in foraging and food consumption or drive costly trade-offs between metabolism and processes such as growth and reproduction.

Download or read book Physiology of Elasmobranch Fishes Structure and Interaction with Environment written by Robert E. Shadwick and published by Academic Press. This book was released on 2015-11-16 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fish Physiology: Physiology of Elasmobranch Fishes, Volume 34A is a useful reference for fish physiologists, biologists, ecologists, and conservation biologists. Following an increase in research on elasmobranchs due to the plight of sharks in today’s oceans, this volume compares elasmobranchs to other groups of fish, highlights areas of interest for future research, and offers perspective on future problems. Covering measurements and lab-and-field based studies of large pelagic sharks, this volume is a natural addition to the renowned Fish Physiology series. Provides needed comprehensive content on the physiology of elasmobranchs Offers a systems approach between structure and interaction with the environment and internal physiology Contains contributions by leading experts in their respective fields, under the guidance of internationally recognized and highly respected editors Highlights areas of interest for future research, including perspective on future problems

Download or read book Temperature and metabolic rate in sedentary fish from the Antarctic North Sea and Indo West Pacific Ocean written by I.A. JOHNSTON and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cardiac Responses to Temperature in Marine Teleosts written by Nishad Jayasundara and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Through evolutionary and acclimatory processes, organisms, including marine teleosts, have modified a common set of biochemical structures and processes to compensate for challenges presented by changes in ambient temperature. Investigating these biological processes underlying thermal optima and thermal limits of ectothermic species is crucial to determining susceptibility of an organism to shifts in their environmental temperature. An insufficient supply of oxygen under thermal stress is thought to underlie thermal limits in aquatic animals including teleost fish. Therefore, to compensate for effects of temperature, organisms may induce an acclimatory response that enhances cardiac performance and oxygen delivery under a new temperature regime. These changes alter the critical threshold of a temperature stress for an organism and thereby maintain or increase its fitness in its environment. The dissertation research presented here investigates effects of temperature acclimation on whole organismal physiology and cellular and molecular processes in cardiac tissues in three physiologically and ecologically distinct perciforme teleosts -- Gillichthys mirabilis, Thunnus orientalis and Trematomus bernacchii. Chapter One focuses on effects of temperature acclimation on thermal limits, metabolic rate, heart rate, oxygen carrying capacity and plasma lactate levels in a highly eurythermal goby species, Gillichthys mirabilis, acclimated to 9oC, 19oC and 26oC for four weeks. Metabolic rate and heart rate measurements were made in fish at their acclimation temperature and when exposed an acute thermal stress. Metabolic rates and plasma lactate levels were also measured in fish recovering from an acute heat stress. Both resting metabolic rates and heart rates at their respective acclimation temperatures did not show a thermal compensatory response with acclimation and maintained elevated rates at warm temperatures. During recovery from an acute stress, only 26oC fish showed post-stress elevation in metabolic rate. Elevated routine and recovery metabolic rates at 26oC suggested an increased energetic cost associated with warm acclimation and when exposed to an acute heat stress; this increased energy demand is possibly to sustain an adequate cellular stress response at high temperatures. Fish acclimated at 19oC and 26oC were able to increase their upper thermal limit and onset of cardiac arrhythmia compared to 9oC-acclimated fish. These data illustrate the pronounced cardiac plasticity and associated phenotypic plasticity of this species. However, this capacity to induce an acclimatory response appears to decrease significantly at temperatures beyond 19oC in G. mirabilis. Chapter Two examined effects of acclimation on cardiac proteome in G. mirabilis acclimated to 9oC, 19oC and 26oC. Proteomic analysis revealed differential expression of proteins involved in cardiac energy metabolism, mitochondrial regulation, iron homeostasis, oxidative stress, cytoprotection against hypoxia, and cytoskeletal reorganization. Proteomic data coupled with in vitro enzyme assay data showed that cardiac energy metabolism, thus aerobic poise of cardiac tissues, is increased in 19oC-acclimated fish compared to 9oC and 26oC-acclimated fish. Overall findings from both Chapters One and Two illustrate that despite their capacity to tolerate a gradient of temperatures, Gillichthys mirabilis exhibit highest cardiac performance near ~19oC, a temperature close to their preferred temperature. Chapter Three investigates the effects of temperature acclimation on cardiorespiratory responses and cardiac and skeletal muscle energy metabolism in a highly stenothermal Antarctic notothenioid, Trematomus bernacchii. Acclimation had no effect on heart rates at resting conditions or the temperatures at which onset of cardiac arrhythmia occurred, suggesting lack of inducible thermal tolerance in cardiac performance in this fish. These data support the hypothesis that cardiac limitations may play a role in reduced thermal tolerance and thermal plasticity of T. bernacchii. Chapter Four examines the effects of acclimation on cardiac transcriptome of endothermic Pacific bluefin tuna Thunnus orientalis acclimated to 14oC, 20oC and 25oC. Overall data indicate that these fish have restored cellular homeostasis at 14oC, potentially optimizing bluefin tuna performance in colder oceans. In contrast, metabolic enzyme activity and gene expression data at 25oC suggest a decrease in total ATP production in cardiac cells, and reduced stress responses. Furthermore, at elevated temperatures cardiac tissues appear to be subjected to heightened oxidative stress and programmed cell death. Together, these data suggest a reduced cardiac performance at ecologically relevant warm temperatures for Pacific bluefin tuna.