Sex‐dependent responses of perch to changes in water clarity and temperature |
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| Authors: | Satu Estlander Leena Nurminen Tomá? Mrkvi?ka Mikko Olin Martti Rask Hannu Lehtonen |
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| Affiliation: | 1. Biological Centre, Academy of Sciences of the Czech Republic, Hydrobiological Institute, ?eské Budějovice, Czech Republic;2. Department of Environmental Sciences/Aquatic Sciences, University of Helsinki, Helsinki, Finland;3. Department of Applied Mathematics and Informatics, Faculty of Economics, University of South Bohemia, ?eské Budějovice, Czech Republic;4. Finnish Game and Fisheries Research Institute, Jyv?skyl?, Finland |
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| Abstract: | Rising temperatures and decreasing water transparency of lakes have strong wide ranging effects on fish. Fish responses to various changes in the environment are usually species‐dependent, but responses may also vary within species. In general, large individuals are considered to be more sensitive to environmental variation due to higher energy demand, than smaller individuals. Similarly, large individuals require more food to maintain bodily functions and are thus more sensitive to resource and food scarcity. These size‐specific responses to environmental gradients are also sex‐dependent in species that exhibit sexual size dimorphism (SSD). We studied in enclosures with short‐term experiments how rising temperatures and decreasing water transparency regulate the feeding rates of female and male European perch (Perca fluviatilis L.). To explore experimental results, we calculated perch SSD in nine lakes with varying environmental conditions using previously collected field data. The results of the experiments revealed that the combined effect of water transparency and temperature on the feeding rate of fish is gender‐dependent: feeding rate of females decreased more than that of males. The experimental results were also supported by field data that revealed a negative relation between water transparency and the magnitude of SSD in perch. Our results suggest that rising temperatures and decreasing water transparency may potentially decrease fish size in a sex‐dependent manner. As female size is one of the main demographic traits determining the reproductive success of a fish population, changing environments may have unexpected and far‐reaching consequences on fish population dynamics. |
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| Keywords: | increasing water colour climate change European perch feeding efficiency sexual size dimorphism |
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