Maternal effects in zooplankton consumers are not only mediated by direct but also by indirect effects of phosphorus limitation

Abstract

Nutrient limitation of primary producers has repeatedly been shown to negatively affect consumers, directly through stoichiometric mismatch and indirectly via alterations in the producer's biochemical quality or palatability. In this study, we assessed whether direct and indirect impacts of phosphorus‐limitation on a planktonic consumer are transferred to the next generation via maternal effects and whether these effects reflect an anticipatory adaptive strategy. For this, we subjected cultures of the algivorous monogonont rotifer Brachionus calyciflorus to three food quality treatments, i.e. P‐limited (LP), P‐replete (HP) and P‐enriched LP algae (i.e. algae with an LP‐growth history but with molar C:P ratios equal to those of HP‐algae). After two generations, we subjected offspring of these cultures to each of the three food quality treatments and monitored life history traits. In addition, we tested starvation resistance. Our results showed very strong negative maternal effects of low P food on offspring performance. These negative effects prevailed irrespective of contemporary diets, suggesting transmissive and selfish maternal effects rather than anticipatory adaptive effects. The relative strength of direct and indirect maternal P‐limitation effects varied among different traits. Adult body size was predominantly determined by direct effects of P‐shortage in maternal as well as contemporary food (LP < LP + P and LP + P = HP). In contrast, whereas egg size was negatively affected by direct effects of P‐limitation in the maternal diet, a contemporary diet of LP and LP + P algae resulted in larger eggs than HP algae. Animals born from such larger eggs showed no higher growth rates, but they were more resistant to starvation, likely as the result of higher maternal allocation of energy rich molecules to the eggs. The present study shows that maternal food conditions represent an important factor that should be taken into account in studies of stoichiometric mismatch between producers and consumers.