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Erratum - Daphnia magna fitness during low food supply under different water temperature and brownification scenarios Texto completo
2018
GALL, Andrea | Kainz, Martin J. | RASCONI, Serena
This corrects the article entitled “Daphnia magna fitness during low food supply under different water temperature and brownification scenarios” by the authors Andrea Gall, Martin J. Kainz and Serena Rasconi, published with DOI 10.4081/jlimnol.2016.1450. The data on somatic growth rates reported in the results section, paragraph “Life history traits”, page 165, were incorrect and the rectified data are presented. Fig. 4 has also been corrected accordingly.
Mostrar más [+] Menos [-]Enhanced anti-predator defence in the presence of food stress in the water flea Daphnia magna Texto completo
2010
Pauwels, Kevin | Stoks, Robby | Meester, Luc de
1. Many prey organisms show adaptive trait shifts in response to predation. These responses are often studied under benign conditions, yet energy stress may be expected to interfere with optimal shifts in trait values. 2. We exposed the water flea Daphnia magna to fish predation and food stress and quantified both life history responses as well as physiological responses (metabolic rate, stress proteins, energy storage and immune function) to explore the architecture of defence strategies in the face of the combined stressors and the occurrence of trade-offs associated with energy constraints. 3. All traits studied showed either an overall or clone-dependent response to food stress. The chronic response to predation risk was less strong for the measured physiological traits than for life history traits, and stronger under food stress than under benign conditions for age at maturity, intrinsic population growth rate and offspring performance (measured as juvenile growth). Immune function (measured as phenoloxidase activity) was lower under predation risk but only at high food, probably because minimum levels were maintained at low food. 4. Overall, food stress induced stronger adaptive predator-induced responses, whereas more energy was invested in reproduction under benign conditions at the cost of being less defended. Our results suggest that food stress may increase the capacity to cope with predation risk and underscore the importance of integrating responses to different stressors and traits, and show how responses towards one stressor can have consequences for the susceptibility to other stressors.
Mostrar más [+] Menos [-]Food web including metazoan parasites for a brackish shallow water ecosystem in Germany and Denmark: Ecological Archives E092‐174 Texto completo
2011
Zander, C Dieter | Josten, Neri | Detloff, Kim C. | Poulin, Robert | McLaughlin, John P. | Thieltges, David W.
This data set presents a food web for the Flensburg Fjord, a brackish shallow water inlet on the Baltic Sea, between Germany and Denmark. The system has a benthic and shallow water pelagic component. This food web has two noteworthy attributes: (1) inclusion of metazoan parasites and other infectious agents and (2) inclusion of ontogenetic stages of parasites with complex life cycles. Data on the free‐living assemblages and parasitism were gathered during original field sampling and supplemented with information from additional published sources and local expert knowledge. Taxonomic resolution is generally high, although some functional or taxonomic groups (e.g., phytoplankton, macroalgae, and several groups of birds) are lumped into single nodes. Each ontogenetic stage of parasites with complex life cycles is treated separately and coded accordingly. For each node, we have included additional information such as taxonomy, life history, residency, and seasonality. Further, for each link, we define a specific interaction type. The web contains 180 nodes, 123 species/assemblages, and 1577 realized links. Of the 123 species/assemblages, 6 are basal, 70 are free‐living, and 45 are infectious. We present the data and metadata in the system‐neutral format standardized by R. F. Hechinger and colleagues, and thus we recognize variables that are not represented in our data set but may be added by further study.
Mostrar más [+] Menos [-]Evaluating the effects of water and food limitation on the life history of an insect using a multiple-stressor framework Texto completo
2022
Padda, Sugjit S. | Stahlschmidt, Zachary R.
Many environmental stressors naturally covary, and the frequency and duration of stressors such as heat waves and droughts are increasing globally with climate change. Multiple stressors may have additive or non-additive effects on fitness-related traits, such as locomotion, reproduction, and somatic growth. Despite its importance to terrestrial animals, water availability is rarely incorporated into multiple-stressor frameworks. Water limitation often occurs concurrently with food limitation (e.g., droughts can trigger famines), and the acquisition of water and food can be linked because water is necessary for digestion and metabolism. Thus, we investigated the independent and interactive effects of water and food limitation on life-history traits using female crickets (Gryllus firmus), which exhibit a wing dimorphism mediating a life-history trade-off between flight and fecundity. Our results indicate that traits vary in their sensitivities to environmental factors and factor–factor interactions. For example, neither environmental factor affected flight musculature, only water limitation affected survival, and food and water availability non-additively (i.e., interactively) influenced body and ovary mass. Water availability had a larger effect on traits than food availability, affected more traits than food availability, and mediated the effects of food availability. Further, life-history strategy influenced the costs of multiple stressors because females investing in flight capacity exhibited greater reductions in body and ovary mass during stress relative to females lacking flight capacity. Therefore, water is important in the multiple-stressor framework, and understanding the dynamics of covarying environmental factors and life history may be critical in the context of climate change characterized by concurrent environmental stressors.
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