1
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Reemeyer JE, Chapman LJ. Effects of acute hypoxia exposure and acclimation on the thermal tolerance of an imperiled Canadian minnow. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024. [PMID: 38966932 DOI: 10.1002/jez.2847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 06/11/2024] [Accepted: 06/19/2024] [Indexed: 07/06/2024]
Abstract
Elevated water temperatures and low dissolved oxygen (hypoxia) are pervasive stressors in aquatic systems that can be exacerbated by climate change and anthropogenic activities, and there is growing interest in their interactive effects. To explore this interaction, we quantified the effects of acute and long-term hypoxia exposure on the critical thermal maximum (CTmax) of Redside Dace (Clinostomus elongatus), a small-bodied freshwater minnow with sparse populations in the Great Lakes Basin of Canada and designated as Endangered under Canada's Species at Risk Act. Fish were held at 18°C and acclimated to four levels of dissolved oxygen (>90%, 60%, 40%, and 20% air saturation). CTmax was measured after 2 and 10 weeks of acclimation and after 3.5 weeks of reoxygenation, and agitation behavior was quantified during CTmax trials. Aquatic surface respiration behavior was also quantified at 14 weeks of acclimation to oxygen treatments. Acute hypoxia exposure decreased CTmax in fish acclimated to normoxia (>90% air saturation), but acclimation to hypoxia reduced this effect. There was no effect of acclimation oxygen level on CTmax when measured in normoxia, and there was no effect of exposure time to hypoxia on CTmax. Residual effects of hypoxia acclimation on CTmax were not seen after reoxygenation. Agitation behavior varied greatly among individuals and was not affected by oxygen conditions. Fish performed aquatic surface respiration with low frequency, but performed it earlier when acclimated to higher levels of oxygen. Overall, this work sheds light on the vulnerability of fish experiencing acute hypoxia and heat waves concurrently.
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Affiliation(s)
| | - Lauren J Chapman
- Department of Biology, McGill University, Quebec, Montreal, Canada
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2
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Lechner ER, Stewart EMC, Frasca VR, Jeffries KM, Wilson CC, Raby GD. Thermal stressors during embryo incubation have limited ontogenic carryover effects in brook trout. J Therm Biol 2024; 122:103880. [PMID: 38850621 DOI: 10.1016/j.jtherbio.2024.103880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/06/2024] [Accepted: 05/24/2024] [Indexed: 06/10/2024]
Abstract
Winter climate is changing rapidly in northern latitudes, and these temperature events have effects on salmonid thermal biology. Stressors during winter egg incubation could reduce hatching success and physiological performance of fall-spawning fishes. Here we quantified the potential for ontogenic carryover effects from embryonic thermal stress in multiple wild and hatchery-origin populations of brook trout (Salvelinus fontinalis), a temperate ectotherm native to northeastern North America. Fertilized eggs from four populations were incubated over the winter in the laboratory in four differing thermal regimes: ambient stream-fed water, chronic warming (+2 °C), ambient with a mid-winter cold-shock, and short-term warming late during embryogenesis (to stimulate an early spring). We examined body size and upper thermal tolerance at the embryonic, fry (10 weeks post-hatch and 27-30 weeks post-hatch) and gravid adult (age 2+) life stages (overall N = 1482). In a separate experiment, we exposed developing embryos to acute seven-day heat stress events immediately following fertilization and at the eyed-egg stage, and then assessed upper thermal tolerance (CTmax) 37 weeks post-hatch. In all cases, fish were raised in common garden conditions after hatch (i.e., same temperatures). Our thermal treatments during incubation had effects that varied by life stage, with incubation temperature and life stage both affecting body size and thermal tolerance. Embryos incubated in warmer treatment groups had higher thermal tolerance; there was no effect of the mid-winter melt event on embryo CTmax. Ten weeks after hatch, fry from the ambient and cold-shock treatment groups had higher and less variable thermal tolerance than did the warmer treatment groups. At 27-30 post-hatch and beyond, differences in thermal tolerance among treatment groups were negligible. Collectively, our study suggests that brook trout only exhibit short-term carryover effects from thermal stressors during embryo incubation, with no lasting effects on phenotype beyond the first few months after hatch.
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Affiliation(s)
- Emily R Lechner
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, K9L 1Z8, Canada.
| | - Erin M C Stewart
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, K9L 1Z8, Canada
| | - Vince R Frasca
- Ontario Ministry of Natural Resources and Forestry, Aquatic Research and Monitoring Section, Codrington Fisheries Research Facility, Codrington, Ontario, K0K 1R0, Canada
| | - Ken M Jeffries
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Chris C Wilson
- Ontario Ministry of Natural Resources and Forestry, Aquatic Research and Monitoring Section, Trent University, Peterborough, Ontario, K9J 7B8, Canada
| | - Graham D Raby
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, K9L 1Z8, Canada; Department of Biology, Trent University, Peterborough, Ontario, K9L IZ8, Canada
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3
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Strait JT, Grummer JA, Hoffman NF, Muhlfeld CC, Narum SR, Luikart G. Local environments, not invasive hybridization, influence cardiac performance of native trout under acute thermal stress. Evol Appl 2024; 17:e13663. [PMID: 38390377 PMCID: PMC10883762 DOI: 10.1111/eva.13663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 12/08/2023] [Accepted: 01/17/2024] [Indexed: 02/24/2024] Open
Abstract
Climate-induced expansion of invasive hybridization (breeding between invasive and native species) poses a significant threat to the persistence of many native species worldwide. In the northern U.S. Rocky Mountains, hybridization between native cutthroat trout and non-native rainbow trout has increased in recent decades due, in part, to climate-driven increases in water temperature. It has been postulated that invasive hybridization may enhance physiological tolerance to climate-induced thermal stress because laboratory studies indicate that rainbow trout have a higher thermal tolerance than cutthroat trout. Here, we assessed whether invasive hybridization improves cardiac performance response to acute water temperature stress of native wild trout populations. We collected trout from four streams with a wide range of non-native admixture among individuals and with different temperature and streamflow regimes in the upper Flathead River drainage, USA. We measured individual cardiac performance (maximum heart rate, "MaxHR", and temperature at arrhythmia, "ArrTemp") during laboratory trials with increasing water temperatures (10-28°C). Across the study populations, we observed substantial variation in cardiac performance of individual trout when exposed to thermal stress. Notably, we found significant differences in the cardiac response to thermal regimes among native cutthroat trout populations, suggesting the importance of genotype-by-environment interactions in shaping the physiological performance of native cutthroat trout. However, rainbow trout admixture had no significant effect on cardiac performance (MaxHR and ArrTemp) within any of the three populations. Our results indicate that invasive hybridization with a warmer-adapted species does not enhance the cardiac performance of native trout under warming conditions. Maintaining numerous populations across thermally and hydrologically diverse stream environments will be crucial for native trout to adapt and persist in a warming climate.
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Affiliation(s)
- Jeffrey T Strait
- Flathead Lake Biological Station, Wildlife Biology Program University of Montana Polson Montana USA
| | - Jared A Grummer
- Flathead Lake Biological Station, Wildlife Biology Program University of Montana Polson Montana USA
| | | | - Clint C Muhlfeld
- U.S. Geological Survey, Northern Rocky Mountain Science Center West Glacier Montana USA
| | - Shawn R Narum
- Columbia River Inter-Tribal Fish Commission Hagerman Idaho USA
| | - Gordon Luikart
- Flathead Lake Biological Station, Wildlife Biology Program University of Montana Polson Montana USA
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4
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Thermal acclimation in brook trout myotomal muscle varies with fiber type and age. Comp Biochem Physiol A Mol Integr Physiol 2023; 276:111354. [PMID: 36464087 DOI: 10.1016/j.cbpa.2022.111354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/23/2022] [Accepted: 11/26/2022] [Indexed: 12/02/2022]
Abstract
As climate change alters the thermal environment of the planet, interest has grown in how animals may mitigate the impact of a changing environment on physiological function. Thermal acclimation to a warm environment may, for instance, blunt the impact of a warming environment on metabolism by allowing a fish to shift to slower isoforms of functionally significant proteins such as myosin heavy chain. The thermal acclimation of brook trout (Salvelinus fontinalis) was examined by comparing swimming performance, myotomal muscle contraction kinetics and muscle histology in groups of fish acclimated to 4, 10 and 20 °C. Brook trout show a significant acclimation response in their maximum aerobic swimming performance (Ucrit), with acclimation to warm water leading to lower Ucrit values. Maximum muscle shortening velocity (Vmax) decreased significantly with warm acclimation for both red or slow-twitch and white or fast-twitch muscle. Immunohistochemical analysis of myotomal muscle suggests changes in myosin expression underly the thermal acclimation of swimming performance and contraction kinetics. Physiological and histological data suggest a robust acclimation response to a warming environment, one that would reduce the added metabolic costs incurred by an ectotherm when environmental temperature rises for sustained periods of time.
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5
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Stewart EMC, Frasca VR, Wilson CC, Raby GD. Short-term acclimation dynamics in a coldwater fish. J Therm Biol 2023; 112:103482. [PMID: 36796924 DOI: 10.1016/j.jtherbio.2023.103482] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 01/11/2023] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
Critical thermal maximum (CTmax) is widely used for measuring thermal tolerance but the strong effect of acclimation on CTmax is a likely source of variation within and among studies/species that makes comparisons more difficult. There have been surprisingly few studies focused on quantifying how quickly acclimation occurs or that combine temperature and duration effects. We studied the effects of absolute temperature difference and duration of acclimation on CTmax of brook trout (Salvelinus fontinalis), a well-studied species in the thermal biology literature, under laboratory conditions to determine how each of the two factors and their combined effects influence critical thermal maximum. Using an ecologically-relevant range of temperatures and testing CTmax multiple times between one and 30 days, we found that both temperature and duration of acclimation had strong effects on CTmax. As predicted, fish that were exposed to warmer temperatures longer had increased CTmax, but full acclimation (i.e., a plateau in CTmax) did not occur by day 30. Therefore, our study provides useful context for thermal biologists by demonstrating that the CTmax of fish can continue to acclimate to a new temperature for at least 30 days. We recommend that this be considered in future studies measuring thermal tolerance that intend to have their organisms fully acclimated to a given temperature. Our results also support using detailed thermal acclimation information to reduce uncertainty caused by local or seasonal acclimation effects and to improve the use of CTmax data for fundamental research and conservation planning.
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Affiliation(s)
- Erin M C Stewart
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, K9J 5G7, Canada.
| | - Vince R Frasca
- Ontario Ministry of Natural Resources and Forestry, Aquatic Research and Monitoring Section, Codrington Fisheries Research Facility, Codrington, ON, K0K 1R0, Canada
| | - Chris C Wilson
- Ontario Ministry of Natural Resources and Forestry, Aquatic Research and Monitoring Section, Trent University, Peterborough, ON, K9J 7B8, Canada
| | - Graham D Raby
- Department of Biology, Trent University, Peterborough, ON, K9J 1Z8, Canada
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6
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Wheeler CR, Lang BJ, Mandelman JW, Rummer JL. The upper thermal limit of epaulette sharks ( Hemiscyllium ocellatum) is conserved across three life history stages, sex and body size. CONSERVATION PHYSIOLOGY 2022; 10:coac074. [PMID: 36583221 PMCID: PMC9795165 DOI: 10.1093/conphys/coac074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 10/17/2022] [Accepted: 11/13/2022] [Indexed: 06/17/2023]
Abstract
Owing to climate change, most notably the increasing frequency of marine heatwaves and long-term ocean warming, better elucidating the upper thermal limits of marine fishes is important for predicting the future of species and populations. The critical thermal maximum (CTmax), or the highest temperature a species can tolerate, is a physiological metric that is used to establish upper thermal limits. Among marine organisms, this metric is commonly assessed in bony fishes but less so in other taxonomic groups, such as elasmobranchs (subclass of sharks, rays and skates), where only thermal acclimation effects on CTmax have been assessed. Herein, we tested whether three life history stages, sex and body size affected CTmax in a tropical elasmobranch, the epaulette shark (Hemiscyllium ocellatum), collected from the reef flats surrounding Heron Island, Australia. Overall, we found no difference in CTmax between life history stages, sexes or across a range of body sizes. Findings from this research suggest that the energetically costly processes (i.e. growth, maturation and reproduction) associated with the life history stages occupying these tropical reef flats do not change overall acute thermal tolerance. However, it is important to note that neither embryos developing in ovo, neonates, nor females actively encapsulating egg cases were observed in or collected from the reef flats. Overall, our findings provide the first evidence in an elasmobranch that upper thermal tolerance is not impacted by life history stage or size. This information will help to improve our understanding of how anthropogenic climate change may (or may not) disproportionally affect particular life stages and, as such, where additional conservation and management actions may be required.
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Affiliation(s)
- Carolyn R Wheeler
- Corresponding author: 1 James Cook Drive, Douglas, Queensland 4814, Australia. Tel: + 61 0480 129 737.
| | - Bethan J Lang
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4814, Australia
| | - John W Mandelman
- School for the Environment, The University of Massachusetts Boston, Boston, MA 02125, USA
- Anderson Cabot Center for Ocean Life, New England Aquarium, Boston, MA 02110, USA
| | - Jodie L Rummer
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4814, Australia
- College of Science and Engineering, James Cook University, Townsville, Queensland 4814, Australia
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7
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Enders EC, Durhack TC. Metabolic rate and critical thermal maximum CTmax estimates for westslope cutthroat trout, Oncorhynchus clarkii lewisi. CONSERVATION PHYSIOLOGY 2022; 10:coac071. [PMID: 36570737 PMCID: PMC9773365 DOI: 10.1093/conphys/coac071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/23/2022] [Accepted: 10/26/2022] [Indexed: 06/17/2023]
Abstract
Global 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 (CTmax ) 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. CTmax 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.
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Affiliation(s)
- Eva C Enders
- Corresponding author: Institute National de la Recherche Scientifique, Centre Eau Terre Environnement, Québec, Québec, G1K 9A9, Canada.
| | - Travis C Durhack
- Fisheries and Oceans Canada, Freshwater Institute, Winnipeg Manitoba, R3T 2N6, Canada
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8
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Venney CJ, Wellband KW, Normandeau E, Houle C, Garant D, Audet C, Bernatchez L. Thermal regime during parental sexual maturation, but not during offspring rearing, modulates DNA methylation in brook charr ( Salvelinus fontinalis). Proc Biol Sci 2022; 289:20220670. [PMID: 35506232 PMCID: PMC9065957 DOI: 10.1098/rspb.2022.0670] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 04/11/2022] [Indexed: 01/04/2023] Open
Abstract
Epigenetic inheritance can result in plastic responses to changing environments being faithfully transmitted to offspring. However, it remains unclear how epigenetic mechanisms such as DNA methylation can contribute to multigenerational acclimation and adaptation to environmental stressors. Brook charr (Salvelinus fontinalis), an economically important salmonid, is highly sensitive to thermal stress and is of conservation concern in the context of climate change. We studied the effects of temperature during parental sexual maturation and offspring rearing on whole-genome DNA methylation in brook charr juveniles (fry). Parents were split between warm and cold temperatures during sexual maturation, mated in controlled breeding designs, then offspring from each family were split between warm (8°C) and cold (5°C) rearing environments. Using whole-genome bisulfite sequencing, we found 188 differentially methylated regions (DMRs) due to parental maturation temperature after controlling for family structure. By contrast, offspring rearing temperature had a negligible effect on offspring methylation. Stable intergenerational inheritance of DNA methylation and minimal plasticity in progeny could result in the transmission of acclimatory epigenetic states to offspring, priming them for a warming environment. Our findings have implications pertaining to the role of intergenerational epigenetic inheritance in response to ongoing climate change.
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Affiliation(s)
- Clare J. Venney
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, QC, Canada G1 V 0A6
| | - Kyle W. Wellband
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, QC, Canada G1 V 0A6
| | - Eric Normandeau
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, QC, Canada G1 V 0A6
| | - Carolyne Houle
- Département de Biologie, Université de Sherbrooke, Sherbrooke, QC, Canada J1 K 2R1
| | - Dany Garant
- Département de Biologie, Université de Sherbrooke, Sherbrooke, QC, Canada J1 K 2R1
| | - Céline Audet
- Institut des sciences de la mer de Rimouski (ISMER), Université du Québec à Rimouski (UQAR), Rimouski, QC, Canada G5 L 2Z9
| | - Louis Bernatchez
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, QC, Canada G1 V 0A6
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9
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Kochhann D, Sarmento CG, de Oliveira JC, Queiroz HL, Val AL, Chapman LJ. Take time to look at the fish: Behavioral response to acute thermal challenge in two Amazonian cichlids. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2021; 335:735-744. [PMID: 34492166 DOI: 10.1002/jez.2541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 08/21/2021] [Accepted: 08/24/2021] [Indexed: 11/11/2022]
Abstract
Critical thermal maximum (CTmax ) is often used as an index of upper thermal tolerance in fishes; however, recent studies have shown that some fishes exhibit agitation or avoidance behavior well before the CTmax is reached. In this study, we quantified behavioral changes during CTmax trials in two Amazonian cichlids, Apistogramma agassizii and Mesonauta insignis. The thermal agitation temperature (Tag ) was recorded as the temperature at which fish left cover and began swimming in an agitated manner, and four behaviors (duration of sheltering, digging, activity, and aquatic surface respiration [ASR]) were compared before and after Tag . Both A. agassizii and M. insignis exhibited high critical thermal maxima, 40.8°C and 41.3°C, respectively. Agitation temperature was higher in M. insignis (37.3°C) than in A. agassizii (35.4°C), indicating that A. agassizii has a lower temperature threshold at which avoidance behavior is initiated. Activity level increased and shelter use decreased with increased temperatures, and patterns were similar between the two species. Digging behavior increased after Tag in both species, but was higher in A. agassazii and may reflect its substrate-oriented ecology. ASR (ventilating water at the surface film) was extremely rare before Tag , but increased in both cichlid species after Tag and was greater in M. insignis than in A. agassizii. This suggests that fish were experiencing physiological hypoxia at water temperatures approaching CTmax . These results demonstrate that acute thermal challenge can induce a suite of behavioral changes in fishes that may provide additional, ecologically relevant information on thermal tolerance.
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Affiliation(s)
- Daiani Kochhann
- Laboratory of Behavioural Ecophysiology, Center of Agrarian and Biological Sciences, Acaraú Valley State University, Sobral, Ceará, Brazil
| | - Carolina G Sarmento
- Laboratory of Ecology and Fish Biology, Mamirauá Institute for Sustainable Development-MISD, Tefé, Brazil
| | - Jomara C de Oliveira
- Laboratory of Ecology and Fish Biology, Mamirauá Institute for Sustainable Development-MISD, Tefé, Brazil.,Amazonas State Secretary for Education and Teaching Quality, SEDUC Amazonas, Manaus, Brazil
| | - Helder L Queiroz
- Laboratory of Ecology and Fish Biology, Mamirauá Institute for Sustainable Development-MISD, Tefé, Brazil
| | - Adalberto L Val
- Laboratory of Ecophysiology and Molecular Evolution, Brazilian National Institute for Research of the Amazon-INPA, Manaus, Brazil
| | - Lauren J Chapman
- Department of Biology, McGill University, Montréal, Québec, Canada
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10
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Firth BL, Drake DAR, Power M. Seasonal and environmental effects on upper thermal limits of eastern sand darter ( Ammocrypta pellucida). CONSERVATION PHYSIOLOGY 2021; 9:coab057. [PMID: 35928053 PMCID: PMC8336138 DOI: 10.1093/conphys/coab057] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 06/15/2023]
Abstract
Anthropogenic stressors are predicted to increase water temperature, which can influence physiological, individual, and population processes in fishes. We assessed the critical thermal maximum (CTmax) of eastern sand darter (Ammocrypta pellucida), a small benthic fish listed as threatened under the Species at Risk Act in Canada. Field trials were conducted stream side June-November 2019 in the Grand River, Ontario, to encompass a range of ambient water temperatures (7-25°C) for which agitation temperature (Tag) and CTmax were determined. Additional measures were taken in the comparatively more turbid Thames River to test the effect of turbidity on both measures. In the Grand, Tag and CTmax ranged from 23°C to 33°C and 27°C to 37°C, respectively, and both significantly increased with ambient water temperature, with a high acclimation response ratio (0.49). The thermal safety margin (difference between ambient temperatures and CTmax) was smallest in July and August (~11°C) indicating that eastern sand darter lives closer to its physiological limit in summer. The between-river comparison indicated that turbidity had no significant influence on Tag and CTmax. Comparison of CTmax with in-river temperatures suggested that mean stream temperature 24 hours before the trial was most important for determining CTmax. Fish mass, temperature variance and maximum temperature in the 24-hour period prior to the CTmax trial were also shown to have some effect on determining CTmax. Overall, study results better define the sensitivity of eastern sand darter to temperature changes across the growing season and provide information to assess the availability of suitable thermal habitat for conservation purposes.
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Affiliation(s)
- Britney L Firth
- Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - D Andrew R Drake
- Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans Canada, Burlington, Ontario L7S 1A1, Canada
| | - Michael Power
- Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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11
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Yates MC, Fraser DJ. Evaluating the correlation between genome-wide diversity and the release of plastic phenotypic variation in experimental translocations to novel natural environments. J Evol Biol 2020; 34:439-450. [PMID: 33274531 DOI: 10.1111/jeb.13747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 11/19/2020] [Indexed: 11/28/2022]
Abstract
Phenotypic reaction norms are often shaped and constrained by selection and are important for allowing organisms to respond to environmental change. However, selection cannot constrain reaction norms for environmental conditions that populations have not experienced. Consequently, cryptic neutral genetic variation for the reaction norm can accumulate such that a release of phenotypic variation occurs upon exposure to novel14 conditions. Most genomic diversity behaves as if functionally neutral. Therefore, genome-wide diversity metrics may correlate with levels of cryptic genetic variation and, as a result, exhibit a positive relationship with a release of phenotypic variation in novel environments. To test this hypothesis, we conducted translocations of juvenile brook trout (Salvelinus fontinalis) from 12 populations to novel uninhabited ponds that represented a gradient of environmental conditions. We assessed reaction norms for morphological traits (body size and four morphometric relative warps) across pond environmental gradients and evaluated the effect of genome-wide heterozygosity on phenotypic variability. All traits displayed plastic reaction norms. Overall, we found some evidence that a release of phenotypic variation consistent with cryptic genetic variation can occur in novel environmental conditions. However, the extent to which this release correlated with average genome-wide diversity was limited to only one of five traits examined. Our results suggest a limited link between genomic diversity26 and the accumulation of cryptic genetic variation in reaction norms. Similarly, reaction norms were constrained for many of the morphological traits examined. Past conditions may have constrained reaction norms in the putatively novel environments despite significant deviations from contemporary source population habitat. Additionally, as a generalist colonizing species brook trout may exhibit plastic phenotypes across a wide range of environmental conditions.
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Affiliation(s)
- Matthew C Yates
- Department of Biology, UQAM, Montreal, QC, Canada.,Group for Interuniversity Research in Limnology and Aquatic Environment (GRIL) at the Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Dylan J Fraser
- Group for Interuniversity Research in Limnology and Aquatic Environment (GRIL) at the Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.,Department of Biology, Concordia University, Montreal, QC, Canada
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12
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Morrison SM, Mackey TE, Durhack T, Jeffrey JD, Wiens LM, Mochnacz NJ, Hasler CT, Enders EC, Treberg JR, Jeffries KM. Sub-lethal temperature thresholds indicate acclimation and physiological limits in brook trout Salvelinus fontinalis. JOURNAL OF FISH BIOLOGY 2020; 97:583-587. [PMID: 32447755 DOI: 10.1111/jfb.14411] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 05/08/2020] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
The upper thermal tolerance of brook trout Salvelinus fontinalis was estimated using critical thermal maxima (CTmax ) experiments on fish acclimated to temperatures that span the species' thermal range (5-25°C). The CTmax increased with acclimation temperature but plateaued in fish acclimated to 20, 23 and 25°C. Plasma lactate was highest, and the hepato-somatic index (IH ) was lowest at 23 and 25°C, which suggests additional metabolic costs at those acclimation temperatures. The results suggest that there is a sub-lethal threshold between 20 and 23°C, beyond which the fish experience reduced physiological performance.
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Affiliation(s)
- Scott M Morrison
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Theresa E Mackey
- Biology Department, University of Winnipeg, Winnipeg, Manitoba, Canada
| | - Travis Durhack
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada
| | - Jennifer D Jeffrey
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Lilian M Wiens
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Neil J Mochnacz
- Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada
| | - Caleb T Hasler
- Biology Department, University of Winnipeg, Winnipeg, Manitoba, Canada
| | - Eva C Enders
- Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada
| | - Jason R Treberg
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ken M Jeffries
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
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13
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Illing B, Downie A, Beghin M, Rummer J. Critical thermal maxima of early life stages of three tropical fishes: Effects of rearing temperature and experimental heating rate. J Therm Biol 2020; 90:102582. [DOI: 10.1016/j.jtherbio.2020.102582] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/20/2020] [Accepted: 03/31/2020] [Indexed: 01/26/2023]
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14
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Turko AJ, Nolan CB, Balshine S, Scott GR, Pitcher TE. Thermal tolerance depends on season, age and body condition in imperilled redside dace Clinostomus elongatus. CONSERVATION PHYSIOLOGY 2020; 8:coaa062. [PMID: 32765883 PMCID: PMC7397480 DOI: 10.1093/conphys/coaa062] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/30/2020] [Accepted: 06/14/2020] [Indexed: 05/19/2023]
Abstract
Urbanization tends to increase water temperatures in streams and rivers and is hypothesized to be contributing to declines of many freshwater fishes. However, factors that influence individual variation in thermal tolerance, and how these may change seasonally, are not well understood. To address this knowledge gap, we studied redside dace Clinostomus elongatus, an imperilled stream fish native to rapidly urbanizing areas of eastern North America. In wild redside dace from rural Ohio, USA, acute upper thermal tolerance (i.e. critical thermal maximum, CTmax) ranged between ~34°C in summer (stream temperature ~22°C) and 27°C in winter (stream temperature ~2°C). Juveniles had higher CTmax than adults in spring and summer, but in winter, CTmax was higher in adults. Thermal safety margins (CTmax - ambient water temperature; ~11°C) were less than the increases in peak water temperature predicted for many redside dace streams due to the combined effects of climate change and urbanization. Furthermore, behavioural agitation occurred 5-6°C below CTmax. Safety margins were larger (>20°C) in autumn and winter. In addition, redside dace were more sensitive (2.5°C lower CTmax) than southern redbelly dace Chrosomus erythrogaster, a non-imperilled sympatric cyprinid. Body condition (Fulton's K) of adult redside dace was positively correlated with CTmax, but in juveniles, this relationship was significant only in one of two summers of experiments. Next, we measured CTmax of captive redside dace fed experimentally manipulated diets. In adults, but not juveniles, CTmax was higher in fish fed a high- vs. low-ration diet, indicating a causal link between nutrition and thermal tolerance. We conclude that redside dace will be challenged by predicted future summer temperatures, especially in urbanized habitats. Thus, habitat restoration that mitigates temperature increases is likely to benefit redside dace. We also suggest habitat restoration that improves food availability may increase thermal tolerance, and thus population resilience.
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Affiliation(s)
- Andy J Turko
- Great Lakes Institute for Environmental Research, University of Windsor, 2990 Riverside Drive West, Windsor, ON, N9C 1A2, Canada
- Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4K1, Canada
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4L8, Canada
- Corresponding author: Great Lakes Institute for Environmental Research, University of Windsor, 2990 Riverside Drive West, Windsor, ON, N9C 1A2, Canada.
| | - Colby B Nolan
- Department of Integrative Biology, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
| | - Sigal Balshine
- Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4K1, Canada
| | - Graham R Scott
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4L8, Canada
| | - Trevor E Pitcher
- Great Lakes Institute for Environmental Research, University of Windsor, 2990 Riverside Drive West, Windsor, ON, N9C 1A2, Canada
- Department of Integrative Biology, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
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15
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Yates MC, Bowles E, Fraser DJ. Small population size and low genomic diversity have no effect on fitness in experimental translocations of a wild fish. Proc Biol Sci 2019; 286:20191989. [PMID: 31771476 DOI: 10.1098/rspb.2019.1989] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Little empirical work in nature has quantified how wild populations with varying effective population sizes and genetic diversity perform when exposed to a gradient of ecologically important environmental conditions. To achieve this, juvenile brook trout from 12 isolated populations or closed metapopulations that differ substantially in population size and genetic diversity were transplanted to previously fishless ponds spanning a wide gradient of ecologically important variables. We evaluated the effect of genome-wide variation, effective population size (Ne), pond habitat, and initial body size on two fitness correlates (survival and growth). Genetic variables had no effect on either fitness correlate, which was determined primarily by habitat (pond temperature, depth, and pH) and initial body size. These results suggest that some vertebrate populations with low genomic diversity, low Ne, and long-term isolation can represent important sources of variation and are capable of maintaining fitness in, and ultimately persisting and adapting to, changing environments. Our results also reinforce the paramount importance of improving available habitat and slowing habitat degradation for species conservation.
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Affiliation(s)
- M C Yates
- Department of Biology, UQAM, Montreal, QC, Canada H3C 3P8.,Group for Interuniversity Research in Limnology and Aquatic Environment (GRIL), Montreal, QC, Canada H3C 3J7
| | - E Bowles
- Department of Biology, Concordia University, Montreal, QC, Canada H4B 1R6
| | - D J Fraser
- Department of Biology, Concordia University, Montreal, QC, Canada H4B 1R6.,Group for Interuniversity Research in Limnology and Aquatic Environment (GRIL), Montreal, QC, Canada H3C 3J7
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16
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Genetic rescue insights from population- and family-level hybridization effects in brook trout. CONSERV GENET 2019. [DOI: 10.1007/s10592-019-01179-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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17
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Acclimation capacity of the cardiac HSP70 and HSP90 response to thermal stress in lake trout (Salvelinus namaycush), a stenothermal ice-age relict. Comp Biochem Physiol B Biochem Mol Biol 2018; 224:53-60. [DOI: 10.1016/j.cbpb.2017.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 12/04/2017] [Accepted: 12/05/2017] [Indexed: 11/18/2022]
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18
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Zastavniouk C, Weir LK, Fraser DJ. The evolutionary consequences of habitat fragmentation: Body morphology and coloration differentiation among brook trout populations of varying size. Ecol Evol 2017; 7:6850-6862. [PMID: 28904765 PMCID: PMC5587476 DOI: 10.1002/ece3.3229] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 05/18/2017] [Accepted: 05/25/2017] [Indexed: 01/15/2023] Open
Abstract
A reduction in population size due to habitat fragmentation can alter the relative roles of different evolutionary mechanisms in phenotypic trait differentiation. While deterministic (selection) and stochastic (genetic drift) mechanisms are expected to affect trait evolution, genetic drift may be more important than selection in small populations. We examined relationships between mature adult traits and ecological (abiotic and biotic) variables among 14 populations of brook trout. These naturally fragmented populations have shared ancestry but currently exhibit considerable variability in habitat characteristics and population size (49 < Nc < 10,032; 3 < Nb < 567). Body size, shape, and coloration differed among populations, with a tendency for more variation among small populations in both trait means and CV when compared to large populations. Phenotypic differences were more frequently and directly linked to habitat variation or operational sex ratio than to population size, suggesting that selection may overcome genetic drift at small population size. Phenotype-environment associations were also stronger in females than males, suggesting that natural selection due to abiotic conditions may act more strongly on females than males. Our results suggest that natural and sexual-selective pressures on phenotypic traits change during the process of habitat fragmentation, and that these changes are largely contingent upon existing habitat conditions within isolated fragments. Our study provides an improved understanding of the ecological and evolutionary consequences of habitat fragmentation and lends insight into the ability of some small populations to respond to selection and environmental change.
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Affiliation(s)
| | - Laura K Weir
- Department of Biology Saint Mary's University Halifax NS Canada
| | - Dylan J Fraser
- Department of Biology Concordia University Montreal QC Canada
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