17 research outputs found
Comparing metabolic rate estimates of two similar salmonids: Salvelinus confluentus and Salvelinus fontinalis
No full textBull Trout (Salvelinus confluentus) occur in many major watersheds in northwestern North America and are identified as “Threatened” or a “Species of Special Concern” in both Canada and the United States. Non-native fishes, including Brook Trout (Salvelinus fontinalis), are one assumed major contributor to declines of Bull Trout populations. Further understanding of how introduced species are affecting Bull Trout populations may help with their recovery. Metabolic rate is an estimate of the amount of energy being used by an organism, and one of the common ways of estimating metabolic rate in fish is through respirometry. In the following research chapters, I conducted intermittent-flow respirometry experiments both in a laboratory setting and a field setting to compare physiological performance via standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope (AS) of Bull Trout and Brook Trout across a range of ecologically relevant temperatures. The temperatures tested are found in the habitat both species currently occupy, as well as temperatures that may be seen in future climate scenarios. Brook Trout tested in Chapter 2 maintained a relatively stable AS across the range of temperatures tested (5, 10, 15, 20, 23°C) and appear to be thermal generalists, well adapted to live in various thermal environments. Brook Trout showed a peak in AS at 15°C, increasing SMR with temperature, and a peak in MMR estimates between 15 and 20°C. Results from Chapter 3 revealed that wild juvenile Bull Trout and Brook Trout have comparable SMR, MMR, and AS when living in sympatry in the natural environment, at least at the temperatures tested (~3°C and ~10°C). Brook Trout have historically been seen as a major threat to Bull Trout populations based on prior studies that have looked at interactions between the species and generally found an advantage for Brook Trout over Bull Trout. However, the results from this study showed similar metabolic rates in both species living in sympatry. The results further suggest that Brook Trout may not have the physiological or temperature related advantages that are expected, at least in regards to aerobic scopeOctober 202
Comparing whole body and red muscle mitochondrial respiration in an active teleost fish, Brook Trout (Salvelinus fontinalis)
No full textUnderstanding how metabolic costs change in relation to increasing temperature under future climate changes is important to predict how ectotherms will be affected across the globe. In fish, whole body respiration is traditionally used to estimate aerobic performance via an organism’s minimum and maximum oxygen consumption rates. However, mitochondria play a crucial role in the aerobic cascade and may be a useful surrogate of aerobic performance. To test if whole body oxygen consumption and mitochondrial capacity are correlated, we estimated whole body metabolic and mitochondrial respiration rates (using permeabilized red muscle fibres) in Brook Trout (Salvelinus fontinalis (Mitchill, 1814) at 10, 15, and 20 °C. Standard metabolic rate increased with acclimation temperature while maximum rates were less sensitive. All mitochondrial respiration rates increased with acclimation temperature, suggesting that red muscle mitochondrial preparations may correlate to the minimal metabolic demands in this species. When expressed as relative rates of electron flow, the red muscle fibres showed no effect of temperature on mitochondrial coupling efficiency. However, there was a pattern of declining capacity to augment respiration via complex II with increasing temperature with a concomitant increase in the capacity of the phosphorylating system relative to maximal rates of mitochondrial electron flow.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Metabolic rate and critical thermal maximum CT(max) estimates for westslope cutthroat trout, Oncorhynchus clarkii lewisi
No full textGlobal warming is changing the thermal habitat of cold-water freshwater fishes, which can lead to decreased fitness and survival and cause shifts in species distributions. The Alberta population of westslope cutthroat trout (Oncorhynchus clarkii lewisi) is listed as ‘Threatened’ under the Canadian Species at Risk Act. The major threats to the species are the alteration in habitat and water flow, competition and hybridization with non-native trout species and climate change. Here, we conducted (i) intermittent-flow respirometry experiments with adult native westslope cutthroat trout and non-native rainbow trout (Oncorhynchus mykiss) and (ii) critical thermal maximum experiments (CT(max)) with adult westslope cutthroat trout to obtain valuable input data for species distribution models. For both species, standard metabolic rate (SMR) was lower at 10°C compared to 15°C and westslope cutthroat trout had higher SMR than rainbow trout. Although there were inter-specific differences in SMR, forced aerobic scope (using a standardized chase protocol) was different at 10°C, but no significant differences were observed at 15°C because of relative smaller differences in maximum metabolic rate between the species. CT(max) of westslope cutthroat trout acclimated to 10°C was 27.0 ± 0.8°C and agitation temperature was 25.2 ± 1.0°C. The results from this study will inform and parametrize cumulative effects assessments and bioenergetics habitat modelling for the recovery planning of the species
Life through a wider scope: Brook Trout (Salvelinus fontinalis) exhibit similar aerobic scope across a broad temperature range
No full textBrook Trout (Salvelinus fontinalis) have been widely introduced throughout the world and are often considered as direct competitors with native salmonid species. Metabolic rate is one metric we can examine to improve our understanding of how well fish perform in different habitats, including across temperature gradients, as metabolism can be directly influenced by environmental temperatures in ectotherms. We estimated the standard metabolic rate, maximum metabolic rate and aerobic scope of lab-reared juvenile Brook Trout (~1 year) using intermittent-flow respirometry across a range of temperatures (5-23°C) likely experienced in the wild. We included a diurnal temperature cycle of ± 1.5°C for each treatment temperature to simulate temporal variation observed in natural waterbodies. Standard metabolic rate and maximum metabolic rate both increased with acclimation temperature before appearing to plateau around 20°C, while mass specific aerobic scope was found to increase from 287.25±13.03 mg O2·kg-1·h-1 at 5°C to a mean of 384.85±13.31 mg O2·kg-1·h-1 at 15°C before dropping at higher temperatures. Although a slight peak was found at 15°C, the generally flat thermal performance curve for aerobic scope suggests Brook Trout are capable of adjusting to a relatively wide range of thermal regimes, appearing to be eurythermal, or a thermal generalist at least for salmonids. The ability of this population to maintain similar physiological performance across a wide range of temperatures may help explain why Brook Trout succeed in a variety of different thermal habitats.This work was supported by Fisheries and Oceans Canada Species at Risk Program and Strategic Program for Ecosystem Research; Dr. J. R. Treberg funding provided by NSERC grant #2018-06052
Metabolic performance and thermal preference of Westslope Cutthroat Trout Oncorhynchus clarkii lewisi and non-native trout across an ecologically relevant range of temperatures
No full textThe physiology and behaviour of fish are strongly affected by ambient water temperature. Physiological traits related to metabolism, such as aerobic scope (AS), can be measured across temperature gradients and the resulting performance curve reflects the thermal niche that fish can occupy. We measured AS of Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi) at 5, 10, 15, 20, and 22C and compared temperature preference (Tpref) of the species to non-native Brook Trout, Brown Trout, and Rainbow Trout. Intermittent-flow respirometry experiments demonstrated that metabolic performance of Westslope Cutthroat Trout was optimal at ~15 C and decreased substantially beyond this temperature, until lethal temperatures at ~25 C. Adjusted preferred temperatures across species (Tpref) were comparatively high, ranging from 17.8-19.9 C, with the highest Tpref observed for Westslope Cutthroat Trout. Results suggest that although Westslope Cutthroat Trout is considered a cold-water species, they do not prefer or perform as well in cold water (≤ 10C), thus, can occupy a warmer thermal niche than previously thought. The metabolic performance curve (AS) can be used to develop species‐specific thermal criteria to delineate important thermal habitats and guide conservation and recovery actions for Westslope Cutthroat Trout.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Additional file 4 of Evidence of effect of riparian attributes on listed freshwater fishes and mussels and their aquatic critical habitat: a systematic map protocol
No full textAdditional file 4. Data coding tool
Additional file 2 of Evidence of effect of riparian attributes on listed freshwater fishes and mussels and their aquatic critical habitat: a systematic map protocol
No full textAdditional file 2. The original search string used in Web of Science used to create the final search string in all databases
Additional file 3 of Evidence of effect of riparian attributes on listed freshwater fishes and mussels and their aquatic critical habitat: a systematic map protocol
No full textAdditional file 3. Benchmark studies used to determine the comprehensiveness of the search strings used
Comparing whole body and red muscle mitochondrial respiration in an active teleost fish, brook trout (<i>Salvelinus fontinalis</i>).
No full textUnderstanding how metabolic costs change in relation to increasing temperature under future climate changes is important to predict how ectotherms will be affected across the globe. In fish, whole body respiration is traditionally used to estimate aerobic performance via an organism’s minimum and maximum oxygen consumption rates. However, mitochondria play a crucial role in the aerobic cascade and may be a useful surrogate of aerobic performance. To test whether whole body oxygen consumption and mitochondrial capacity are correlated, we estimated whole body metabolic and mitochondrial respiration rates (using permeabilized red muscle fibres) in brook trout ( Salvelinus fontinalis (Mitchill, 1814)) at 10, 15, and 20 °C. Standard metabolic rate increased with acclimation temperature, while maximum rates were less sensitive. All mitochondrial respiration rates increased with acclimation temperature, suggesting that red muscle mitochondrial preparations may correlate to the minimal metabolic demands in this species. When expressed as relative rates of electron flow, the red muscle fibres showed no effect of temperature on mitochondrial coupling efficiency. However, there was a pattern of declining capacity to augment respiration via complex II with increasing temperature with a concomitant increase in the capacity of the phosphorylating system relative to maximal rates of mitochondrial electron flow
A comparison of tag retention and mortality from two tagging methods for internal tag placement in Channel Catfish.
No full textObjective: Documenting the movement of Channel Catfish Ictalurus punctatus through telemetry, where a transmitter tag is surgically implanted in the fish, can provide valuable insight into the species' spatial ecology and habitat use. However, since fish in the order Siluriformes can expel foreign objects such as tags from their body cavity, the utility of telemetry technology may be limited for Channel Catfish. This study aimed to determine (1) how quickly Channel Catfish reject tags that were surgically implanted into the body cavity, (2) if surgical implantation of transmitter tags causes mortality, and (3) what surgical method is best to minimize tag rejection and/or mortality.Methods: Three surgical trials were conducted on Channel Catfish (n= 24) using two tag implantation methods: a nontethered method, in which the tag was freely implanted into the body cavity, and a tethered method, where the tag was attached to the pectoral girdle. Fish were observed in the lab for 30 days for trials 1 and 2 and 225 days for trial 3 following tag implantation.Result: No complete tag rejections occurred during any of the three experimental tri-als. However, all five tethered fish experienced mortality during trial 3 (58–221 days postsurgery). Necropsies indicated that the tethered tagging method led to septicae-mia infections and internal lacerations from the tether, which were not observed in the nontethered fish. Tags in the nontethered fish were in the process of being absorbed into the intestinal tract, which over time might have led to tag rejection.Conclusion: While rejection is possibly the end point of the nontethered tagging method, our results suggest it is nevertheless the better tagging method for Channel Catfish given higher survival
