Fred Sundström | Uppsala University (original) (raw)
Papers by Fred Sundström
The Journal of experimental biology, Jan 15, 2016
Thermal plasticity of cardiorespiratory function allows ectotherms like fish to cope with seasona... more Thermal plasticity of cardiorespiratory function allows ectotherms like fish to cope with seasonal temperature changes and is critical for resilience to climate change. Yet, the chronic thermal effects on cardiovascular homeostatic reflexes in fish are little understood although this may have important implications for physiological performance and overall resilience to climate warming. We compared cardiac autonomic control and baroreflex regulation of heart rate in perch (Perca fluviatilis L.) from a reference area in the Baltic Sea at 18-19°C with conspecifics from the Biotest enclosure, a chronically heated ecosystem receiving warmed effluent water (24-25°C) from a nuclear power plant. Resting heart rate of Biotest fish displayed clear thermal compensation and was 58.3±2.3 beats min(-1) compared with 52.4±2.6 beats min(-1) in reference fish at their respective environmental temperatures (Q10=1.2). The thermally compensated heart rate of Biotest fish was a combined effect of eleva...
Environmental Biology of Fishes, 2001
PLoS ONE, 2011
This study explored if boldness could be used to predict social status. First, boldness was asses... more This study explored if boldness could be used to predict social status. First, boldness was assessed by monitoring individual zebrafish behaviour in (1) an unfamiliar barren environment with no shelter (open field), (2) the same environment when a roof was introduced as a shelter, and (3) when the roof was removed and an unfamiliar object (LegoH brick) was introduced. Next, after a resting period of minimum one week, social status of the fish was determined in a dyadic contest and dominant/subordinate individuals were determined as the winner/loser of two consecutive contests. Multivariate data analyses showed that males were bolder than females and that the behaviours expressed by the fish during the boldness tests could be used to predict which fish would later become dominant and subordinate in the ensuing dyadic contest. We conclude that bold behaviour is positively correlated to dominance in zebrafish and that boldness is not solely a consequence of social dominance.
Ethology, 2003
Growth hormone (GH) gene transgenesis has allowed the production of salmon with an inherently inc... more Growth hormone (GH) gene transgenesis has allowed the production of salmon with an inherently increased growth potential, on average two to threefold higher compared with daily specific growth rates observed in normal, non-transgenic fish. This difference quickly ...
Journal of Fish Biology, 2010
In this study, individual growth patterns of wild-type and growth-enhanced coho salmon Oncorhynch... more In this study, individual growth patterns of wild-type and growth-enhanced coho salmon Oncorhynchus kisutch at 8, 12 and 16 degrees C water temperature were followed. Despite large differences among individuals in growth rates, there was generally little variation in the shape of the growth curves among O. kisutch individuals of both genotypes and at all temperatures. Typically, individuals that were relatively large initially were also relatively large at the end of the growth period. The limitation in variation was more pronounced in the growth-enhanced O. kisutch than in the wild type, where the relative size of some individuals reared at 12 and 8 degrees C changed by the end of the trial. As a warmer temperature seems to decrease the plasticity of growth trajectories in wild-type fish, it is possible that global warming will influence the ability of wild fish to adapt their growth to changing conditions.
Ethology, 2003
Growth hormone (GH) gene transgenesis has allowed the production of salmon with an inherently inc... more Growth hormone (GH) gene transgenesis has allowed the production of salmon with an inherently increased growth potential, on average two to threefold higher compared with daily specific growth rates observed in normal, non-transgenic fish. This difference quickly results in animals of very different sizes at age, and is associated with specific morphological effects and enhanced appetites in transgenic animals. However, less is known of the feeding and antipredator behaviour of GH-transgenic fish, information that can help with predictions of potential ecological consequences of release or escape of transgenic fish into the wild. In a series of experiments, transgenic (T) and normal (N) coho salmon of varying age and size (from 0.5 to 40 g, 3.5-21 mo) were studied singly, in pairs, and in groups during feeding and simulated predation threat. Vertical position generally did not differ between T and N fry, but at larger size (>4 g) T fish remained closer to the surface than N fish both during feeding and predatory attacks, probably as a consequence of inherent differences in feeding motivation and later reinforcement by associative learning. This difference in vertical position was not the result of competition as it remained even after either fish in the pair had been removed. In nature, where predators may attack from above (birds) or below (fish), this kind of behaviour may translate into higher risk of predation, which could increase mortality and lower the fitness of transgenic fish, unless their increased growth rate can compensate for the increased risk-taking.
Journal of Fish Biology, 2010
In this study, individual growth patterns of wild-type and growth-enhanced coho salmon Oncorhynch... more In this study, individual growth patterns of wild-type and growth-enhanced coho salmon Oncorhynchus kisutch at 8, 12 and 16 • C water temperature were followed. Despite large differences among individuals in growth rates, there was generally little variation in the shape of the growth curves among O. kisutch individuals of both genotypes and at all temperatures. Typically, individuals that were relatively large initially were also relatively large at the end of the growth period. The limitation in variation was more pronounced in the growth-enhanced O. kisutch than in the wild type, where the relative size of some individuals reared at 12 and 8 • C changed by the end of the trial. As a warmer temperature seems to decrease the plasticity of growth trajectories in wild-type fish, it is possible that global warming will influence the ability of wild fish to adapt their growth to changing conditions.
Thermal plasticity of cardiorespiratory function allows ectotherms like fish to cope with seasona... more Thermal plasticity of cardiorespiratory function allows ectotherms like fish to cope with seasonal temperature changes and is critical for resilience to climate change. Yet, the chronic thermal effects on cardiovascular homeostatic reflexes in fish are little understood although this may have important implications for physiological performance and overall resilience to climate warming. We compared cardiac autonomic control and baroreflex regulation of heart rate in perch (Perca fluviatilis L.) from a reference area in the Baltic Sea at 18–19°C with conspecifics from the Biotest enclosure, a chronically heated ecosystem receiving warmed effluent water (24–25°C) from a nuclear power plant. Resting heart rate of Biotest fish displayed clear thermal compensation and was 58.3±2.3 beats min −1 compared with 52.4±2.6 beats min −1 in reference fish at their respective environmental temperatures (Q 10 =1.2). The thermally compensated heart rate of Biotest fish was a combined effect of elevated inhibitory cholinergic tone (105% in Biotest fish versus 70% in reference fish) and reduced intrinsic cardiac pacemaker rate. A barostatic response was evident in both groups, as pharmacologically induced increases and decreases in blood pressure resulted in atropine-sensitive bradycardia and tachycardia, respectively. Yet, the tachycardia in Biotest fish was significantly greater, presumably due to the larger scope for vagal release. Acclimation of Biotest fish to 18°C for 3 weeks abolished differences in intrinsic heart rate and autonomic tone, suggesting considerable short-term thermal plasticity of cardiovascular control in this species. The heightened hypotensive tachycardia in Biotest perch may represent an important mechanism of ectothermic vertebrates that safeguards tissue perfusion pressure when tissue oxygen demand is elevated by environmental warming.
PLoS ONE, 2011
This study explored if boldness could be used to predict social status. First, boldness was asses... more This study explored if boldness could be used to predict social status. First, boldness was assessed by monitoring individual zebrafish behaviour in (1) an unfamiliar barren environment with no shelter (open field), (2) the same environment when a roof was introduced as a shelter, and (3) when the roof was removed and an unfamiliar object (LegoH brick) was introduced. Next, after a resting period of minimum one week, social status of the fish was determined in a dyadic contest and dominant/subordinate individuals were determined as the winner/loser of two consecutive contests. Multivariate data analyses showed that males were bolder than females and that the behaviours expressed by the fish during the boldness tests could be used to predict which fish would later become dominant and subordinate in the ensuing dyadic contest. We conclude that bold behaviour is positively correlated to dominance in zebrafish and that boldness is not solely a consequence of social dominance. Citation: Dahlbom SJ, Lagman D, Lundstedt-Enkel K, Sundströ m LF, Winberg S (2011) Boldness Predicts Social Status in Zebrafish (Danio rerio). PLoS ONE 6(8): e23565.
Ethology, 2004
We compared the performance of normal and growth hormone-transgenic coho salmon feeding on surfac... more We compared the performance of normal and growth hormone-transgenic coho salmon feeding on surface drifting edible and inedible novel prey items in various social environments. With an inherently higher appetite, we predicted that transgenic fish would be more willing to feed on novel prey, and that visual company with another fish would enhance this difference further. Transgenic and normal fish, of similar size and age, were equally willing to attack both the edible (live insects) and inedible (artificial angling lure flies) prey, but transgenic fish did so faster and were more likely to make repeated attacks. Transgenic fish managed to seize and consume the edible prey after fewer attacks than did normal fish. However, swallowing of prey took longer than for normal fish. More transgenic individuals interacted with the inedible prey compared with normal salmon, and initially, transgenic fish in visual company with another fish also interacted more with the prey than single transgenic or any constellation of normal focal fish. With repeated exposures, the number of individuals attacking and the number of interactions with the prey decreased. These responses were stronger in transgenic fish, partly explained by the initially low response in normal fish. The observed differences are most likely the consequences of elevated levels of growth hormone in transgenic fish generating enhanced feeding motivation and reinforcement capacity. In a natural environment, the performance of a growth hormone-transgenic fish may therefore depend on the relative abundance of profitable vs. unprofitable prey, as well as the presence of other transgenic individuals.
The consequences of elevated temperature on body shape were investigated by comparing European pe... more The consequences of elevated temperature on body shape were investigated by comparing European perch Perca fluviatilis from the Forsmark area of the Baltic Sea to P. fluviatilis from a nearby Biotest enclosure. The Biotest is a man-made enclosure within the Baltic Sea that has received warm water from a nuclear power plant since 1980, resulting in temperatures that are elevated 5–10 ∘ C relative to the surrounding Baltic Sea. Sampled fish ranged from young-of-the-year to 14 years. Geometric mor-phometrics and multivariate statistical analysis revealed significant morphological differences between individuals of P. fluviatilis from these two habitats. Most importantly, relative shape changed with size, with small individuals of P. fluviatilis from Biotest being characterized by a deeper body shape and a larger caudal peduncle than the smaller Baltic individuals. In large specimens, smaller differences were found with Biotest individuals being more slender than Baltic individuals. These results show that, in order to have a full understanding of the biological effects of elevated temperatures, studies that cover the entire size range of organisms will be important. Apart from the direct influence of temperature on growth rate and body shape, other ecological factors affected by temperature are discussed as possible contributors to the observed differences between the two populations.
PLoS ONE, 2014
This study explored if boldness could be used to predict social status. First, boldness was asses... more This study explored if boldness could be used to predict social status. First, boldness was assessed by monitoring individual zebrafish behaviour in (1) an unfamiliar barren environment with no shelter (open field), (2) the same environment when a roof was introduced as a shelter, and (3) when the roof was removed and an unfamiliar object (LegoH brick) was introduced. Next, after a resting period of minimum one week, social status of the fish was determined in a dyadic contest and dominant/subordinate individuals were determined as the winner/loser of two consecutive contests. Multivariate data analyses showed that males were bolder than females and that the behaviours expressed by the fish during the boldness tests could be used to predict which fish would later become dominant and subordinate in the ensuing dyadic contest. We conclude that bold behaviour is positively correlated to dominance in zebrafish and that boldness is not solely a consequence of social dominance. Citation: Dahlbom SJ, Lagman D, Lundstedt-Enkel K, Sundströ m LF, Winberg S (2011) Boldness Predicts Social Status in Zebrafish (Danio rerio). PLoS ONE 6(8): e23565.
The Journal of experimental biology, Jan 15, 2016
Thermal plasticity of cardiorespiratory function allows ectotherms like fish to cope with seasona... more Thermal plasticity of cardiorespiratory function allows ectotherms like fish to cope with seasonal temperature changes and is critical for resilience to climate change. Yet, the chronic thermal effects on cardiovascular homeostatic reflexes in fish are little understood although this may have important implications for physiological performance and overall resilience to climate warming. We compared cardiac autonomic control and baroreflex regulation of heart rate in perch (Perca fluviatilis L.) from a reference area in the Baltic Sea at 18-19°C with conspecifics from the Biotest enclosure, a chronically heated ecosystem receiving warmed effluent water (24-25°C) from a nuclear power plant. Resting heart rate of Biotest fish displayed clear thermal compensation and was 58.3±2.3 beats min(-1) compared with 52.4±2.6 beats min(-1) in reference fish at their respective environmental temperatures (Q10=1.2). The thermally compensated heart rate of Biotest fish was a combined effect of eleva...
Environmental Biology of Fishes, 2001
PLoS ONE, 2011
This study explored if boldness could be used to predict social status. First, boldness was asses... more This study explored if boldness could be used to predict social status. First, boldness was assessed by monitoring individual zebrafish behaviour in (1) an unfamiliar barren environment with no shelter (open field), (2) the same environment when a roof was introduced as a shelter, and (3) when the roof was removed and an unfamiliar object (LegoH brick) was introduced. Next, after a resting period of minimum one week, social status of the fish was determined in a dyadic contest and dominant/subordinate individuals were determined as the winner/loser of two consecutive contests. Multivariate data analyses showed that males were bolder than females and that the behaviours expressed by the fish during the boldness tests could be used to predict which fish would later become dominant and subordinate in the ensuing dyadic contest. We conclude that bold behaviour is positively correlated to dominance in zebrafish and that boldness is not solely a consequence of social dominance.
Ethology, 2003
Growth hormone (GH) gene transgenesis has allowed the production of salmon with an inherently inc... more Growth hormone (GH) gene transgenesis has allowed the production of salmon with an inherently increased growth potential, on average two to threefold higher compared with daily specific growth rates observed in normal, non-transgenic fish. This difference quickly ...
Journal of Fish Biology, 2010
In this study, individual growth patterns of wild-type and growth-enhanced coho salmon Oncorhynch... more In this study, individual growth patterns of wild-type and growth-enhanced coho salmon Oncorhynchus kisutch at 8, 12 and 16 degrees C water temperature were followed. Despite large differences among individuals in growth rates, there was generally little variation in the shape of the growth curves among O. kisutch individuals of both genotypes and at all temperatures. Typically, individuals that were relatively large initially were also relatively large at the end of the growth period. The limitation in variation was more pronounced in the growth-enhanced O. kisutch than in the wild type, where the relative size of some individuals reared at 12 and 8 degrees C changed by the end of the trial. As a warmer temperature seems to decrease the plasticity of growth trajectories in wild-type fish, it is possible that global warming will influence the ability of wild fish to adapt their growth to changing conditions.
Ethology, 2003
Growth hormone (GH) gene transgenesis has allowed the production of salmon with an inherently inc... more Growth hormone (GH) gene transgenesis has allowed the production of salmon with an inherently increased growth potential, on average two to threefold higher compared with daily specific growth rates observed in normal, non-transgenic fish. This difference quickly results in animals of very different sizes at age, and is associated with specific morphological effects and enhanced appetites in transgenic animals. However, less is known of the feeding and antipredator behaviour of GH-transgenic fish, information that can help with predictions of potential ecological consequences of release or escape of transgenic fish into the wild. In a series of experiments, transgenic (T) and normal (N) coho salmon of varying age and size (from 0.5 to 40 g, 3.5-21 mo) were studied singly, in pairs, and in groups during feeding and simulated predation threat. Vertical position generally did not differ between T and N fry, but at larger size (>4 g) T fish remained closer to the surface than N fish both during feeding and predatory attacks, probably as a consequence of inherent differences in feeding motivation and later reinforcement by associative learning. This difference in vertical position was not the result of competition as it remained even after either fish in the pair had been removed. In nature, where predators may attack from above (birds) or below (fish), this kind of behaviour may translate into higher risk of predation, which could increase mortality and lower the fitness of transgenic fish, unless their increased growth rate can compensate for the increased risk-taking.
Journal of Fish Biology, 2010
In this study, individual growth patterns of wild-type and growth-enhanced coho salmon Oncorhynch... more In this study, individual growth patterns of wild-type and growth-enhanced coho salmon Oncorhynchus kisutch at 8, 12 and 16 • C water temperature were followed. Despite large differences among individuals in growth rates, there was generally little variation in the shape of the growth curves among O. kisutch individuals of both genotypes and at all temperatures. Typically, individuals that were relatively large initially were also relatively large at the end of the growth period. The limitation in variation was more pronounced in the growth-enhanced O. kisutch than in the wild type, where the relative size of some individuals reared at 12 and 8 • C changed by the end of the trial. As a warmer temperature seems to decrease the plasticity of growth trajectories in wild-type fish, it is possible that global warming will influence the ability of wild fish to adapt their growth to changing conditions.
Thermal plasticity of cardiorespiratory function allows ectotherms like fish to cope with seasona... more Thermal plasticity of cardiorespiratory function allows ectotherms like fish to cope with seasonal temperature changes and is critical for resilience to climate change. Yet, the chronic thermal effects on cardiovascular homeostatic reflexes in fish are little understood although this may have important implications for physiological performance and overall resilience to climate warming. We compared cardiac autonomic control and baroreflex regulation of heart rate in perch (Perca fluviatilis L.) from a reference area in the Baltic Sea at 18–19°C with conspecifics from the Biotest enclosure, a chronically heated ecosystem receiving warmed effluent water (24–25°C) from a nuclear power plant. Resting heart rate of Biotest fish displayed clear thermal compensation and was 58.3±2.3 beats min −1 compared with 52.4±2.6 beats min −1 in reference fish at their respective environmental temperatures (Q 10 =1.2). The thermally compensated heart rate of Biotest fish was a combined effect of elevated inhibitory cholinergic tone (105% in Biotest fish versus 70% in reference fish) and reduced intrinsic cardiac pacemaker rate. A barostatic response was evident in both groups, as pharmacologically induced increases and decreases in blood pressure resulted in atropine-sensitive bradycardia and tachycardia, respectively. Yet, the tachycardia in Biotest fish was significantly greater, presumably due to the larger scope for vagal release. Acclimation of Biotest fish to 18°C for 3 weeks abolished differences in intrinsic heart rate and autonomic tone, suggesting considerable short-term thermal plasticity of cardiovascular control in this species. The heightened hypotensive tachycardia in Biotest perch may represent an important mechanism of ectothermic vertebrates that safeguards tissue perfusion pressure when tissue oxygen demand is elevated by environmental warming.
PLoS ONE, 2011
This study explored if boldness could be used to predict social status. First, boldness was asses... more This study explored if boldness could be used to predict social status. First, boldness was assessed by monitoring individual zebrafish behaviour in (1) an unfamiliar barren environment with no shelter (open field), (2) the same environment when a roof was introduced as a shelter, and (3) when the roof was removed and an unfamiliar object (LegoH brick) was introduced. Next, after a resting period of minimum one week, social status of the fish was determined in a dyadic contest and dominant/subordinate individuals were determined as the winner/loser of two consecutive contests. Multivariate data analyses showed that males were bolder than females and that the behaviours expressed by the fish during the boldness tests could be used to predict which fish would later become dominant and subordinate in the ensuing dyadic contest. We conclude that bold behaviour is positively correlated to dominance in zebrafish and that boldness is not solely a consequence of social dominance. Citation: Dahlbom SJ, Lagman D, Lundstedt-Enkel K, Sundströ m LF, Winberg S (2011) Boldness Predicts Social Status in Zebrafish (Danio rerio). PLoS ONE 6(8): e23565.
Ethology, 2004
We compared the performance of normal and growth hormone-transgenic coho salmon feeding on surfac... more We compared the performance of normal and growth hormone-transgenic coho salmon feeding on surface drifting edible and inedible novel prey items in various social environments. With an inherently higher appetite, we predicted that transgenic fish would be more willing to feed on novel prey, and that visual company with another fish would enhance this difference further. Transgenic and normal fish, of similar size and age, were equally willing to attack both the edible (live insects) and inedible (artificial angling lure flies) prey, but transgenic fish did so faster and were more likely to make repeated attacks. Transgenic fish managed to seize and consume the edible prey after fewer attacks than did normal fish. However, swallowing of prey took longer than for normal fish. More transgenic individuals interacted with the inedible prey compared with normal salmon, and initially, transgenic fish in visual company with another fish also interacted more with the prey than single transgenic or any constellation of normal focal fish. With repeated exposures, the number of individuals attacking and the number of interactions with the prey decreased. These responses were stronger in transgenic fish, partly explained by the initially low response in normal fish. The observed differences are most likely the consequences of elevated levels of growth hormone in transgenic fish generating enhanced feeding motivation and reinforcement capacity. In a natural environment, the performance of a growth hormone-transgenic fish may therefore depend on the relative abundance of profitable vs. unprofitable prey, as well as the presence of other transgenic individuals.
The consequences of elevated temperature on body shape were investigated by comparing European pe... more The consequences of elevated temperature on body shape were investigated by comparing European perch Perca fluviatilis from the Forsmark area of the Baltic Sea to P. fluviatilis from a nearby Biotest enclosure. The Biotest is a man-made enclosure within the Baltic Sea that has received warm water from a nuclear power plant since 1980, resulting in temperatures that are elevated 5–10 ∘ C relative to the surrounding Baltic Sea. Sampled fish ranged from young-of-the-year to 14 years. Geometric mor-phometrics and multivariate statistical analysis revealed significant morphological differences between individuals of P. fluviatilis from these two habitats. Most importantly, relative shape changed with size, with small individuals of P. fluviatilis from Biotest being characterized by a deeper body shape and a larger caudal peduncle than the smaller Baltic individuals. In large specimens, smaller differences were found with Biotest individuals being more slender than Baltic individuals. These results show that, in order to have a full understanding of the biological effects of elevated temperatures, studies that cover the entire size range of organisms will be important. Apart from the direct influence of temperature on growth rate and body shape, other ecological factors affected by temperature are discussed as possible contributors to the observed differences between the two populations.
PLoS ONE, 2014
This study explored if boldness could be used to predict social status. First, boldness was asses... more This study explored if boldness could be used to predict social status. First, boldness was assessed by monitoring individual zebrafish behaviour in (1) an unfamiliar barren environment with no shelter (open field), (2) the same environment when a roof was introduced as a shelter, and (3) when the roof was removed and an unfamiliar object (LegoH brick) was introduced. Next, after a resting period of minimum one week, social status of the fish was determined in a dyadic contest and dominant/subordinate individuals were determined as the winner/loser of two consecutive contests. Multivariate data analyses showed that males were bolder than females and that the behaviours expressed by the fish during the boldness tests could be used to predict which fish would later become dominant and subordinate in the ensuing dyadic contest. We conclude that bold behaviour is positively correlated to dominance in zebrafish and that boldness is not solely a consequence of social dominance. Citation: Dahlbom SJ, Lagman D, Lundstedt-Enkel K, Sundströ m LF, Winberg S (2011) Boldness Predicts Social Status in Zebrafish (Danio rerio). PLoS ONE 6(8): e23565.