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Meuthen D, Reinhold K. On the use of antibiotics in plasticity research: Gastropod shells unveil a tale of caution. J Anim Ecol 2023; 92:1055-1064. [PMID: 36869422 DOI: 10.1111/1365-2656.13909] [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] [Accepted: 02/24/2023] [Indexed: 03/05/2023]
Abstract
Through phenotypic plasticity, individual genotypes can produce multiple phenotypes dependent on the environment. In the modern world, anthropogenic influences such as man-made pharmaceuticals are increasingly prevalent. They might alter observable patterns of plasticity and distort our conclusions regarding the adaptive potential of natural populations. Antibiotics are nowadays nearly ubiquitous in aquatic environments and prophylactic antibiotic use is also becoming more common to optimize animal survival and reproductive output in artificial settings. In the well-studied plasticity model system Physella acuta, prophylactic erythromycin treatment acts against gram-positive bacteria and thereby reduces mortality. Here, we study its consequences for inducible defence formation in the same species. In a 2 × 2 split-clutch design, we reared 635 P. acuta in either the presence or absence of this antibiotic, followed by 28-day exposure to either high or low predation risk as perceived through conspecific alarm cues. Under antibiotic treatment, risk-induced increases in shell thickness, a well-known plastic response in this model system, were larger and consistently detectable. Antibiotic treatment reduced shell thickness in low-risk individuals, suggesting that in controls, undiscovered pathogen infection increased shell thickness under low risk. Family variation in risk-induced plasticity was low, but the large variation in responses to antibiotics among families suggests different pathogen susceptibility between genotypes. Lastly, individuals that developed thicker shells had reduced total mass, which highlights resource trade-offs. Antibiotics thus have the potential to uncover a larger extent of plasticity, but might counterintuitively distort plasticity estimates for natural populations where pathogens are a part of natural ecology.
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Affiliation(s)
- Denis Meuthen
- Evolutionary Biology, Bielefeld University, Bielefeld, Germany
| | - Klaus Reinhold
- Evolutionary Biology, Bielefeld University, Bielefeld, Germany
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2
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Batabyal A, Chau D, Rivi V, Lukowiak K. Risk in one is not risk in all: snails show differential decision making under high- and low-risk environments. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Henry J, Brand JA, Bai Y, Martin JM, Wong BBM, Wlodkowic D. Multi-generational impacts of exposure to antidepressant fluoxetine on behaviour, reproduction, and morphology of freshwater snail Physa acuta. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 814:152731. [PMID: 34974022 DOI: 10.1016/j.scitotenv.2021.152731] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 12/08/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Contamination of the environment by pharmaceutical pollutants poses an increasingly critical threat to aquatic ecosystems around the world. This is particularly true of psychoactive compounds, such as antidepressant drugs, which have become ubiquitous contaminants and have been demonstrated to modify aquatic animal behaviours at very low concentrations (i.e. ng/L). Despite raising risks to the hydrosphere, there is a notable paucity of data on the long term, multigenerational effects of antidepressants at environmentally realistic concentrations. Moreover, current research has predominantly focused on mean-level effects, with little research on variation among and within individuals when considering key behavioural traits. In this work, we used a multigenerational exposure of a freshwater snail (Physa acuta) to an environmentally relevant concentration of the antidepressant fluoxetine (mean measured concentration: 32.7 ng/L, SE: 2.3). The snails were allowed to breed freely in large mesocosm populations over 3 years. Upon completion of the exposure, we repeatedly measured the locomotory activity (624 measures total), reproductive output (234 measures total) as well as morphometric endpoints (78 measures total). While we found no mean-level differences between treatments in locomotory activities, we did find that fluoxetine exposed snails (n = 46) had significantly reduced behavioural plasticity (i.e. VW; within-individual variation) in activity levels compared to unexposed snails (n = 32). As a result, fluoxetine exposed snails demonstrated significant behavioural repeatability, which was not the case for unexposed snails. Further, we report a reduction in egg mass production in fluoxetine exposed snails, and a marginally non-significant difference in morphology between treatment groups. These results highlight the potential detrimental effects of long-term fluoxetine exposure on non-target organisms at environmentally realistic dosages. Additionally, our findings demonstrate the underappreciated potential for psychoactive contaminants to have impacts beyond mean-level effects, with consequences for population resilience to current and future environmental challenges.
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Affiliation(s)
- Jason Henry
- The Neurotox Lab, School of Science, RMIT University, Melbourne, VIC 3083, Australia
| | - Jack A Brand
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Yutao Bai
- The Neurotox Lab, School of Science, RMIT University, Melbourne, VIC 3083, Australia
| | - Jake M Martin
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Bob B M Wong
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Donald Wlodkowic
- The Neurotox Lab, School of Science, RMIT University, Melbourne, VIC 3083, Australia.
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Haave-Audet E, Besson AA, Nakagawa S, Mathot KJ. Differences in resource acquisition, not allocation, mediate the relationship between behaviour and fitness: a systematic review and meta-analysis. Biol Rev Camb Philos Soc 2021; 97:708-731. [PMID: 34859575 DOI: 10.1111/brv.12819] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 11/29/2022]
Abstract
Within populations, individuals often show repeatable variation in behaviour, called 'animal personality'. In the last few decades, numerous empirical studies have attempted to elucidate the mechanisms maintaining this variation, such as life-history trade-offs. Theory predicts that among-individual variation in behavioural traits could be maintained if traits that are positively associated with reproduction are simultaneously associated with decreased survival, such that different levels of behavioural expression lead to the same net fitness outcome. However, variation in resource acquisition may also be important in mediating the relationship between individual behaviour and fitness components (survival and reproduction). For example, if certain phenotypes (e.g. dominance or aggressiveness) are associated with higher resource acquisition, those individuals may have both higher reproduction and higher survival, relative to others in the population. When individuals differ in their ability to acquire resources, trade-offs are only expected to be observed at the within-individual level (i.e. for a given amount of resource, if an individual increases its allocation to reproduction, it comes at the cost of allocation to survival, and vice versa), while among individuals traits that are associated with increased survival may also be associated with increased reproduction. We performed a systematic review and meta-analysis, asking: (i) do among-individual differences in behaviour reflect among-individual differences in resource acquisition and/or allocation, and (ii) is the relationship between behaviour and fitness affected by the type of behaviour and the testing environment? Our meta-analysis consisted of 759 estimates from 193 studies. Our meta-analysis revealed a positive correlation between pairs of estimates using both survival and reproduction as fitness proxies. That is, for a given study, behaviours that were associated with increased reproduction were also associated with increased survival, suggesting that variation in behaviour at the among-individual level largely reflects differences among individuals in resource acquisition. Furthermore, we found the same positive correlation between pairs of estimates using both survival and reproduction as fitness proxies at the phenotypic level. This is significant because we also demonstrated that these phenotypic correlations primarily reflect within-individual correlations. Thus, even when accounting for among-individual differences in resource acquisition, we did not find evidence of trade-offs at the within-individual level. Overall, the relationship between behaviour and fitness proxies was not statistically different from zero at the among-individual, phenotypic, and within-individual levels; this relationship was not affected by behavioural category nor by the testing condition. Our meta-analysis highlights that variation in resource acquisition may be more important in driving the relationship between behaviour and fitness than previously thought, including at the within-individual level. We suggest that this may come about via heterogeneity in resource availability or age-related effects, with higher resource availability and/or age leading to state-dependent shifts in behaviour that simultaneously increase both survival and reproduction. We emphasize that future studies examining the mechanisms maintaining behavioural variation in populations should test the link between behavioural expression and resource acquisition - both within and among individuals. Such work will allow the field of animal personality to develop specific predictions regarding the mediating effect of resource acquisition on the fitness consequences of individual behaviour.
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Affiliation(s)
- Elène Haave-Audet
- Department of Biological Sciences, University of Alberta, CW 405, Biological Sciences Bldg, Edmonton, AB, T6G 2E9, Canada
| | - Anne A Besson
- Department of Biological Sciences, University of Alberta, CW 405, Biological Sciences Bldg, Edmonton, AB, T6G 2E9, Canada.,Department of Zoology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| | - Shinichi Nakagawa
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Kimberley J Mathot
- Department of Biological Sciences, University of Alberta, CW 405, Biological Sciences Bldg, Edmonton, AB, T6G 2E9, Canada.,Canada Research Chair, Integrative Ecology, Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
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Kawaguchi M, Kuriwada T. Effect of predator cue on escape and oviposition behaviour of freshwater snail. BEHAVIOUR 2020. [DOI: 10.1163/1568539x-bja10018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
When suitability of sites for parent is incompatible with that for their eggs, parent–offspring conflict occurs — the parent must choose between the optimal oviposition site for eggs and that suitable for itself. We examined effects of predator cue on parental habitat use and oviposition site in Physa acuta. We assessed desiccation risk in eggs and the relationship between water depth and predation risk. Predator cues induced the elevation of parental habitat away from the bottom but had no effect on the oviposition site. Oviposition site choice is not by-product of escape response. Eggs that were exposed to desiccation failed to hatch, indicating high desiccation risk. Eggs laid at deeper levels were at higher risk of stripping from oviposition substrates by crayfishes. Although the middle-water level would be suitable oviposition sites, the parents selected an oviposition site in the upper level. There are other benefits and costs of oviposition site selection.
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Affiliation(s)
- Manami Kawaguchi
- Kagoshima University, Faculty of Education, Laboratory of Zoology, Korimoto 1-20-6, Kagoshima 890-0065, Japan
| | - Takashi Kuriwada
- Kagoshima University, Faculty of Education, Laboratory of Zoology, Korimoto 1-20-6, Kagoshima 890-0065, Japan
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Secondi J, Raux F. An invasive amphibian drives antipredator responses in two prey at different trophic positions. Behav Ecol 2020. [DOI: 10.1093/beheco/araa036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Generalist invasive predators consume prey at different trophic levels and generate drastic changes in local communities. However, the long-term effects of predation may be reduced by eco-evolutionary responses of native populations. The capacity of prey species distributed across the trophic network to develop antipredator responses may determine the ecosystem potential to buffer against the invader. The African clawed frog is a major invader on several continents. Because of its large size, generalist diet, and aquatic lifestyle, we predicted the development of antipredator responses in prey species at different trophic levels. We tested for behavioral shifts between populations within and outside the invasive range in the herbivorous snail Physella acuta and the predatory heteropteran, the backswimmer Notonecta glauca. We detected antipredator responses in both prey species. In sympatry, P. acuta stayed higher in the water column, while N. glauca spent more time swimming underwater and less time surfacing when the predator cues were present. In allopatry, P. acuta dived deeper and N. glauca spent more time surfacing and stayed longer still underwater. In both species, sympatric populations showed evidence of olfactory recognition of the frog. Our results show that the introduction of a top predator like Xenopus laevis in the pond ecosystem drives behavioral antipredator responses in species across the trophic network. Eco-evolutionary processes may allow some degree of long-term resilience of pond communities to the invasion of X. laevis.
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Affiliation(s)
- Jean Secondi
- UMR5023 LEHNA, ENTPE, CNRS, University of Lyon, Université Claude Bernard Lyon 1, 43, Boulevard du 11 novembre 1918, F-69622 Villeurbanne, France
- Faculté des sciences, Université d’Angers, 2 bld Lavoisier, F-49045 Angers, France
| | - Fanny Raux
- Faculté des sciences, Université d’Angers, 2 bld Lavoisier, F-49045 Angers, France
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Cinel SD, Hahn DA, Kawahara AY. Predator-induced stress responses in insects: A review. JOURNAL OF INSECT PHYSIOLOGY 2020; 122:104039. [PMID: 32113954 DOI: 10.1016/j.jinsphys.2020.104039] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 04/26/2018] [Accepted: 02/26/2020] [Indexed: 06/10/2023]
Abstract
Predators can induce extreme stress and profound physiological responses in prey. Insects are the most dominant animal group on Earth and serve as prey for many different predators. Although insects have an extraordinary diversity of anti-predator behavioral and physiological responses, predator-induced stress has not been studied extensively in insects, especially at the molecular level. Here, we review the existing literature on physiological predator-induced stress responses in insects and compare what is known about insect stress to vertebrate stress systems. We conclude that many unrelated insects share a baseline pathway of predator-induced stress responses that we refer to as the octopamine-adipokinetic hormone (OAH) axis. We also present best practices for studying predator-induced stress responses in prey insects. We encourage investigators to compare neurophysiological responses to predator-related stress at the organismal, neurohormonal, tissue, and cellular levels within and across taxonomic groups. Studying stress-response variation between ecological contexts and across taxonomic levels will enable the field to build a holistic understanding of, and distinction between, taxon- and stimulus-specific responses relative to universal stress responses.
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Affiliation(s)
- Scott D Cinel
- Department of Biology, University of Florida, Gainesville, FL 32611, USA; Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.
| | - Daniel A Hahn
- Department of Entomology & Nematology, University of Florida, Gainesville, FL 32611, USA
| | - Akito Y Kawahara
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
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Moiron M, Laskowski KL, Niemelä PT. Individual differences in behaviour explain variation in survival: a meta-analysis. Ecol Lett 2019; 23:399-408. [PMID: 31811699 DOI: 10.1111/ele.13438] [Citation(s) in RCA: 147] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/13/2019] [Accepted: 11/07/2019] [Indexed: 12/22/2022]
Abstract
Research focusing on among-individual differences in behaviour ('animal personality') has been blooming for over a decade. Central theories explaining the maintenance of such behavioural variation posits that individuals expressing greater "risky" behaviours should suffer higher mortality. Here, for the first time, we synthesize the existing empirical evidence for this key prediction. Our results did not support this prediction as there was no directional relationship between riskier behaviour and greater mortality; however there was a significant absolute relationship between behaviour and survival. In total, behaviour explained a significant, but small, portion (5.8%) of the variance in survival. We also found that risky (vs. "shy") behavioural types live significantly longer in the wild, but not in the laboratory. This suggests that individuals expressing risky behaviours might be of overall higher quality but the lack of predation pressure and resource restrictions mask this effect in laboratory environments. Our work demonstrates that individual differences in behaviour explain important differences in survival but not in the direction predicted by theory. Importantly, this suggests that models predicting behaviour to be a mediator of reproduction-survival trade-offs may need revision and/or empiricists may need to reconsider their proxies of risky behaviours when testing such theory.
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Affiliation(s)
- Maria Moiron
- Centre d'Ecologie Fonctionnelle et Evolutive, UMR 5175 Campus CNRS, Montpellier, France
| | - Kate L Laskowski
- Department of Evolution and Ecology, University of California Davis, Davis, CA, USA
| | - Petri T Niemelä
- Behavioural Ecology, Department of Biology, Ludwig-Maximilians University of Munich, Planegg-Martinsried, Germany
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Hamman EA, McCoy MW. Top-down pulses reduce prey population sizes and persistence. Sci Rep 2018; 8:9346. [PMID: 29921899 PMCID: PMC6008325 DOI: 10.1038/s41598-018-27661-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/29/2018] [Indexed: 11/09/2022] Open
Abstract
Resource pulses are well documented and have important consequences for population dynamics relative to continuous inputs. However, pulses of top-down factors (e.g. predation) are less explored and appreciated in the ecological literature. Here, we use a simple differential equation population model to show how pulsed removals of individuals from a population alter population size relative to continuous dynamics. Pulsed removals result in lower equilibrium population sizes relative to continuous removals, and the differences are greatest at low population growth rates, high removal rates, and with large, infrequent pulses. Furthermore, the timing of the removal pulses (either stochastic or cyclic) affects population size. For example, cyclic removals are less likely than stochastic removals to result in population eradication, but when eradication occurs, the time until eradication is shorter for cyclic than with stochastic removals.
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Affiliation(s)
| | - Michael W McCoy
- Department of Biology, East Carolina University, Greenville, USA
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