Phenotypic plasticity in life‐history traits of Daphnia galeata in response to temperature – a comparison across clonal lineages separated in time

Abstract

Climatic changes are projected to result in rapid adaptive events with considerable phenotypic shifts. In order to reconstruct the impact of increased mean water temperatures during past decades and to reveal possible thermal micro‐evolution, we applied a resurrection ecology approach using dormant eggs of the freshwater keystone species Daphnia galeata. To this end, we compared the adaptive response of D. galeata clones from Lake Constance of two different time periods, 1965–1974 (“historical”) versus 2000–2009 (“recent”), to experimentally increased temperature regimes. In order to distinguish between genetic versus environmentally induced effects, we performed a common garden experiment in a flow‐through system and measured variation in life‐history traits. Experimental thermal regimes were chosen according to natural temperature conditions during the reproductive period of D. galeata in Central European lakes, with one additional temperature regime exceeding the currently observable maximum (+2°C). Increased water temperatures were shown to significantly affect measured life‐history traits, and significant “temperature × clonal age” interactions were revealed. Compared to historical clones, recent clonal lineages exhibited a shorter time to first reproduction and a higher survival rate, which may suggest temperature‐driven micro‐evolution over time but does not allow an explicit conclusion on the adaptive nature of such responses.

Population‐level responses to temperature, density and clonal differences in Daphnia magna as revealed by integral projection modelling

“…Moreover, individuals initially grew faster, but this effect reversed at larger sizes. These plastic responses on growth and maturation have previously been described for Daphnia (Henning‐Lucass et al., ; Mitchell & Lampert, ; Van Doorslaer et al., ) and are believed to be important in generating the temperature‐size rule, which is followed by the majority of ectotherms (Atkinson, , ). Survival was negatively affected by temperature, in agreement with previous studies (MacArthur & Baillie, , but see Henning‐Lucass et al., ).…”

“…Gust et al., ), as well as in studies on rapid evolution and eco‐evolutionary dynamics (De Meester, Van Doorslaer, Geerts, Orsini, & Stoks, ; Hairston et al., ; Van Doorslaer et al., , ). In addition, various factors have been shown to affect specific vital rates, such as effects of temperature (Henning‐Lucass, Cordellier, Streit, & Schwenk, ), genetic background (Henning‐Lucass et al., ; Pietrzak, ), food concentration (Gabsi, Glazier, Hammers‐Wirtz, Ratte, & Preuss, ) and population density (Guisande, ). Daphnia magna individuals reproduce parthenogenetically when environmental conditions are favourable and switch to sexual reproduction when conditions worsen (Kleiven, Larsson, & Hobæk, ), which results in the production of long‐lived dormant eggs.…”

Population transcriptomics in Daphnia: The role of thermal selection

“…The clonal lines were established using hatchlings from propagules collected from the sediment (see Henning‐Lucass et al. () for hatching conditions and Herrmann et al. () for sediment sampling conditions).…”

When males outlive females: Sex‐specific effects of temperature on lifespan in a cyclic parthenogen

“…Recently, Johnston and Snell () observed that lifespans of closely related rotifer species respond differently to temperature manipulation. Even more closely, Henning‐Lucass, Cordellier, Streit, and Schwenk (), studying the response to temperature in Daphnia galeata clones of different age (i.e., hatched from resting eggs of different age), found no overall effect of temperature on Daphnia survival rate, as individuals from clones of different age reacted differently.…”