Changes in water conditions interact to affect how Trinidadian guppies defend themselves from predators, scientists at the University of Bristol have discovered.
Known stressors, such as increased temperature and reduced visibility, when combined, cause these fish to be less likely to avoid a predator, and importantly, form looser protective shoals.
The findings, published today in the journal Proceedings of the Royal Society Bshow that the responses of guppies are more affected by the interaction of these stressors than if they act independently.
Natural habitats face increasing environmental challenges due to human activities such as land use change, exploitation and climate change.
Lead author Costanza Zanghi from Bristol’s School of Biological Sciences, explained, “Of all the possible environmental parameters that can stress a system, we decided to focus on increasing temperature and water hardness due to as previous research has shown that visual animals, like most fish, are greatly affected by them.
“We know that warmer water affects fish’s swimming ability and hunger levels, and we also know that increased turbulence, such as darkness, can change how visual predators and victim interact with each other.
“In this research we want to take these common stressors, which are known to be developing in freshwater habitats around the world, and see how the visual response that fish each other when they are under these stressors at the same time.
“This is important and novel because sometimes, especially when several stressors change the same behavior in different ways, the overall result can be very different from what is shown in studies where only one stressor is tested. That because these stressors can interact in unpredictable ways.”
The team observed responses between a predator and a prey group under four treatments, optimal housing conditions (as a control), and treatments where water temperature or cloudiness rose. They were then tested in an interaction treatment where temperature and turbulence were increased at the same time.
It took several weeks of lab tests involving 36 predators and 288 prey fish. The animals are separated so that they are not harmed.
All the video recordings are then processed to get a good movement of all the fish so that the researchers can calculate the swimming speed of all the fish and how they are connected to each other: how close the prey stays and how each prey is far from the predator. trying to stay.
Co-author Milly Munro, who joined the Ioannou Group specifically for this project said, “The opportunity to be involved in this study with the team was a wonderful experience, and I am grateful to have been awarded ASAB’s Undergraduate Scholarship funding. Designing and conducting research with Costanza and the team was excellent as my first experience in academic research. I learned many valuable skills and insights into what it takes to design and conduct a study in this class, everything I got from this experience really helps me in current and future projects.”
Zanghi said, “The inclusion of multi-stressors in such experiments will improve the ecological relevance and applicability of the findings.
“In natural environments, organisms rarely experience isolated stressors but face complex combinations of stressors. By investigating how organisms respond to these realistic scenarios, the research will be more applicable to conservation and management efforts.
“This provides insights into how organisms cope and adapt to multiple stressors, helping to develop effective strategies for mitigating the negative effects of environmental change.”
Now the team plans to test whether the reduction in anti-predator behavior is as negative for the prey as it seems and is not a smart adaptation to allow the prey fish to worry less about predators in an environment. that keeps them safe. By using a wider range of predators, they will also examine whether these changes may affect many species differently.
Zanghi concluded, “This study is exciting because it introduces significant ecological complexity in the context of predator-prey interactions.
“By including additional stressors and specifically testing potential interactions between these factors, this study greatly contributes to our understanding of the dynamics between prey and their predators in a rapidly changing in the world.”
More information:
Costanza Zanghi et al, Temperature and disturbance interact synergistically to alter anti-predator behavior in the Trinidadian guppy, Proceedings of the Royal Society B: Biological Sciences (2023). DOI: 10.1098/rspb.2023.0961. royalsocietypublishing.org/doi … .1098/rspb.2023.0961
Provided by the University of Bristol
Citation: Warmer, darker waters favor guppies’ predators, study finds (2023, July 4) retrieved July 4, 2023 from https://phys.org/news/2023-07-warmer-murkier -favor-predators-guppies.html
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