| 1. |
- Koeck, Barbara, et al.
(author)
-
Angling selects against active and stress-resilient phenotypes in rainbow trout
- 2019
-
In: Canadian Journal of Fisheries and Aquatic Sciences. - : Canadian Science Publishing. - 0706-652X .- 1205-7533. ; 76:2, s. 320-333
-
Journal article (peer-reviewed)abstract
- Selection induced by human harvest can lead to different patterns of phenotypic change than selection induced by natural predation and could be a major driving force of evolution of wild populations. The vulnerability of individuals to angling depends on the individual decision to ingest the bait, possibly mediated by their neuroendocrine response towards the associated stimulus. To investigate the mechanisms behind individual vulnerability to angling, we conducted angling experiments in replicated ponds and quantified individual behavioral traits and neuroendocrine stress responsiveness in two salmonid species, rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta). We discovered a phenotypic syndrome in rainbow trout, but not in brown trout, where lower serotonergic and dopaminergic brain activity and cortisol levels (i.e., lower stress responsiveness) in response to a standardized experimental stressor were associated with higher activity, forming a proactive phenotype that showed increased vulnerability to angling. Our results show that angling targets the most stress-resilient and active phenotypes of rainbow trout, supporting the suggestion that fishing-induced phenotypic selection may lead to an increased representation of stress-responsive and low-activity phenotypes in harvested populations.
|
|
| 2. |
|
|
| 3. |
- Lennox, Robert J., et al.
(author)
-
A role for lakes in revealing the nature of animal movement using high dimensional telemetry systems
- 2021
-
In: Movement Ecology. - : BioMed Central. - 2051-3933. ; 9:1
-
Research review (peer-reviewed)abstract
- Movement ecology is increasingly relying on experimental approaches and hypothesis testing to reveal how, when, where, why, and which animals move. Movement of megafauna is inherently interesting but many of the fundamental questions of movement ecology can be efficiently tested in study systems with high degrees of control. Lakes can be seen as microcosms for studying ecological processes and the use of high-resolution positioning systems to triangulate exact coordinates of fish, along with sensors that relay information about depth, temperature, acceleration, predation, and more, can be used to answer some of movement ecology's most pressing questions. We describe how key questions in animal movement have been approached and how experiments can be designed to gather information about movement processes to answer questions about the physiological, genetic, and environmental drivers of movement using lakes. We submit that whole lake telemetry studies have a key role to play not only in movement ecology but more broadly in biology as key scientific arenas for knowledge advancement. New hardware for tracking aquatic animals and statistical tools for understanding the processes underlying detection data will continue to advance the potential for revealing the paradigms that govern movement and biological phenomena not just within lakes but in other realms spanning lands and oceans.
|
|
| 4. |
- Wallerius, Magnus L., et al.
(author)
-
Socially induced stress and behavioural inhibition in response to angling exposure in rainbow trout
- 2019
-
In: Fisheries Management and Ecology. - : Wiley. - 0969-997X .- 1365-2400. ; 26:6, s. 611-620
-
Journal article (peer-reviewed)abstract
- It is well known that fish can learn to avoid angling gear after experiencing a catch-and-release event, that is, after a private hooking experience. However, the possible importance of social information cues and their influence on an individual's vulnerability to angling remains largely unexplored, that is, social experience of a conspecific capture. The effects of private and social experience of hooking on the stress response of fish and subsequent catch rates were examined. Hatchery-reared rainbow trout, Oncorhynchus mykiss (Walbaum), were implanted with heart rate loggers and experimentally subjected to private or social experience of hooking. Private and social experience of angling induced an increased heart rate in fish compared with naive control fish. While private experience of hooking explained most of the reduced vulnerability to capture, no clear evidence was found that social experience of hooking affected angling vulnerability in fish that had never been hooked before. While both private and social experiences of angling constitute significant physiological stressors for rainbow trout, only the private experience reduces an individual's vulnerability to angling and in turn affecting population-level catchability.
|
|
| 5. |
- Zavorka, Libor, et al.
(author)
-
Co-existence with non-native brook trout breaks down the integration of phenotypic traits in brown trout parr
- 2017
-
In: Functional Ecology. - : Wiley. - 0269-8463 .- 1365-2435. ; 31:8, s. 1582-1591
-
Journal article (peer-reviewed)abstract
- 1. A phenotypic syndrome refers to complex patterns of integration among functionally related traits in an organism that defines how the organism interacts with its environment and sustains itself. 2. Human-induced biological invasions have become important sources of environmental modifications. However, the extent to which invasive species affect the phenotypic syndromes of individuals in a native is currently unknown. Such knowledge has important implications for understanding ecological interactions and the management of biological invasions. 3. Here, field monitoring in a natural stream were combined with standardized estimates of behavioral, physiological and morphological traits to address the hypothesis that coexistence with a non-native invader induces a novel environmental pressure that disrupts the adaptive integration among phenotypic traits of the native species. We compared the strength of integration among key phenotypic traits (i.e. aerobic scope, standard metabolic rate, body growth, activity, and body shape) and ecological niche traits (i.e. spring and summer diet, home range size, daily movements) of an allopatric group of native brown trout (Salmo trutta) with a group of brown trout living in sympatry with non-native brook trout (Salvelinus fontinalis). 4. We found that the integration of phenotypic traits was substantially reduced in the sympatric brown trout and that allopatric and sympatric brown trout differed in key phenotypic and ecological niche traits. Brown trout living in sympatry with non-native brook trout consumed more terrestrial prey, had smaller home ranges, and a stouter body shape. Sympatric brown trout also had lower specific growth rate, suggesting a lower fitness. 5. The results are generally in line with our hypothesis suggesting that the reduction in fitness observed in sympatric brown trout is caused by the breakdown of their adaptive phenotypic syndrome. This may be caused by differences in the plasticity of the response of phenotypic traits to the novel selection pressure induced by the non-native species. Our results may help explaining deleterious effects of non-native species reported in the absence of direct competition with the native species.
|
|
| 6. |
- Zavorka, L., et al.
(author)
-
Laboratory captivity can affect scores of metabolic rates and activity in wild brown trout
- 2019
-
In: Journal of Zoology. - : Wiley. - 0952-8369 .- 1469-7998. ; 307:4, s. 249-255
-
Journal article (peer-reviewed)abstract
- Phenotypic scoring of wild animals under standardized laboratory conditions is important as it allows field ecologists and evolutionary biologists to understand the development and maintenance of interindividual differences in plastic traits (e.g. behaviour and physiology). However, captivity is associated with a shift from a natural familiar environment to an unfamiliar and artificial environment, which may affect estimates of plastic phenotypic traits. In this study, we tested how previous experience with laboratory environments and time spent in captivity affects behavioural (i.e. activity) and metabolic (i.e. standard and maximum metabolic rates) scoring of our model species, wild brown trout Salmo trutta. We found that individuals with previous experience of laboratory captivity (10.5 months earlier) showed higher activity in an open field test than individuals with no prior experience of laboratory captivity. Previous experience with captivity had no significant effect on metabolic rates. However, metabolic rates seemed to increase with increasing time spent in captivity prior to the collection of measurements. Although there are benefits of keeping wild animals in captivity prior to scoring, our results suggest that while allowing for sufficient acclimatization researchers should aim at minimizing time in captivity of wild animals to increase accuracy and ecological relevance of the scoring of plastic phenotypic traits.
|
|
