Inter- and intraspecific differences in rotifer fatty acid composition during acclimation to low quality food

Biochemical food quality constraints affect the performance of consumers and mediate trait variation among and within consumer species. To assess inter- and intraspecific differences in fatty acid retention and conversion in freshwater rotifers, we provided four strains of two closely related rotifer species, Brachionus calyciflorus sensu stricto and Brachionus fernandoi, with food algae differing in their fatty acid composition. The rotifers grazed for five days on either Nannochloropsis limnetica or Monoraphidium minutum, two food algae with distinct polyunsaturated fatty acid (PUFA) profiles, before the diets were switched to PUFA-free Synechococcus elongatus, which was provided for three more days. We found between- and within-species differences in rotifer fatty acid compositions on the respective food sources and, in particular, highly specific acclimation reactions to the PUFA-free diet. The different reactions indicate inter- but also intraspecific differences in physiological t...