The interplay of past and current stress exposure on the water flea Daphnia

Abstract

Summary1. Natural populations are exposed to multiple stressors, including both anthropogenic challenges such as xenobiotics and natural stressors associated with exposure to parasites and predators. While there is increasing concern and interest in the combined impact of current exposure to multiple stressors, little attention has been given to how past exposure to a stressor and its evolutionary response shapes the effects of current stressors. 2. Here, we performed a life-table experiment using the water flea Daphnia magna to study combined effects of current exposure to the pesticide carbaryl, parasite spores and fish predation risk and how these effects depend upon past exposure to carbaryl using clones obtained from a previous carbaryl selection experiment. 3. The current exposure to all three treatments affected life-history traits. Exposure to fish kairomones increased intrinsic population growth rate, while carbaryl and parasite exposure decreased this fitness measure. The three treatments interacted only in a few cases: carbaryl and fish kairomone exposure interacted in shaping intrinsic population growth rate and its component individual reproductive performance, yet the latter only in the animals not exposed to carbaryl stress in the past. 4. Our data revealed not only adaptive evolution of carbaryl resistance but also associated evolutionary costs in terms of reduced resistance to parasites, corroborating results of an earlier study. Importantly, both the evolutionary benefits and costs of past exposure to carbaryl stress were conditional on current environmental conditions, exposure to predation risk and parasites, respectively. 5. The emerging pattern showed that past stress interacted with current stress in shaping life history. Such evolution-driven carry-over effects across generations have been often ignored and may complicate the prediction of effects of current exposure to single and combined stressors even long after the past stress has disappeared.

Adaptive phenotypic plasticity and local adaptation for temperature tolerance in freshwater zooplankton

“…A second problem often encountered in temperature local adaptation studies is the nature of the biological traits assessed. Life-history fitness components such as growth, maturation and fecundity are known to adapt to local demographic conditions such as food availability or predator pressure [34][35][36][37] and thus may disguise patterns of local adaptation to temperature. We therefore use short-term ability to tolerate extreme temperatures, a concept used successfully to test for local adaptation in other aquatic systems [10,38,39], where the key variable is the ability to maintain elementary body functions under such extremes.…”

Pesticide exposure impacts not only hatching of dormant eggs, but also hatchling survival and performance in the water flea Daphnia magna

“…1, number 3); (iii) change the fitness and reproductive traits of parthenogenetic females (Fig. 1, number 4) (Barata et al 2007;Hassold and Backhaus 2009;Jansen et al 2011); (iv) change offspring sex ratio (Fig. 1, number 5) (Dodson et al 1999;Olmstead and LeBlanc 2003;Tatarazako and Oda 2007;Palma et al 2009);and (v) affect timing and amount of dormant egg production (Fig.…”

Progressive acclimation alters interaction between salinity and temperature in experimental Daphnia populations

“…This loss of temperature-dependence due to past environmental conditions is a complex interaction scenario, which was observed both in acute and chronic endpoints, although much more consistently in the latter (juvenile growth assays). As emphasized by other authors (Jansen et al, 2011;Seeland et al, 2012;Scherer et al, 2013), such interactive and potentially confounding scenarios -using multiple stress factors and considering the influence of environmental context -must be taken into account in extrapolations and predictions used in the risk assessment of stressors, especially under a climate change framework (Noyes et al, 2009). The interaction between temperature and salinity has been studied previously with cladocerans (Hall and Burns, 2002;Brucet et al, 2009;Ismail et al, 2011;Chen and Stillman, 2012).…”

“…Acclimation processes are important in the evaluation of the effects of contaminants in natural populations, because there is an important role of maternal effects, persisting throughout different generations (Chen and Stillman, 2012), and a redistribution of energy under stress (Paul et al, 2004;Guan and Wang, 2006), which can subsequently affect responses to all sorts of environmental variability. Indeed, some authors (Jansen et al, 2011;Seeland et al, 2012) have shown that past environmentally-stressful conditions produce evolution-driven carry-over effects across generations, thus complicating the prediction of the future risk of such stressors for the environment. Modifications in the tolerance limits of Daphnia after acclimation have been demonstrated for other stressors in multigenerational studies, including metals (Bossuyt et al, 2005;Guan and Wang, 2006;Chen and Stillman, 2012) and organic pesticides (Jansen et al, 2011;Seeland et al, 2012).…”

“…However, this is dependent on the degree of environmental variability and the long-term effects of acclimation (Chen and Stillman, 2012;Stoks et al, 2014). There are still insufficient studies that consider pre-adaptation or acclimation in the sensitivity or resilience of organisms and populations to the interactive effects of simultaneous stressors (Ismail et al, 2011;Jansen et al, 2011;Chen and Stillman, 2012;Fischer et al, 2013).…”