Nucleic Acid Content in Crustacean Zooplankton: Bridging Metabolic and Stoichiometric Predictions Bullejos Carrillo, Francisco José Carrillo Lechuga, Presentación Gorokhova, Elena Medina Sánchez, Juan Manuel Villar Argáiz, Manuel High mountain lake Fresh water zooplankton Growth rate Life history Dry weight Ultraviolet radiation Elemental composition Climate change RNA Phosphorus Metabolic and stoichiometric theories of ecology have provided broad complementary principles to understand ecosystem processes across different levels of biological organization. We tested several of their cornerstone hypotheses by measuring the nucleic acid (NA) and phosphorus (P) content of crustacean zooplankton species in 22 high mountain lakes (Sierra Nevada and the Pyrenees mountains, Spain). The P-allocation hypothesis (PAH) proposes that the genome size is smaller in cladocerans than in copepods as a result of selection for fast growth towards P-allocation from DNA to RNA under P limitation. Consistent with the PAH, the RNA:DNA ratio was >8-fold higher in cladocerans than in copepods, although ‘fast-growth’ cladocerans did not always exhibit higher RNA and lower DNA contents in comparison to ‘slow-growth’ copepods. We also showed strong associations among growth rate, RNA, and total P content supporting the growth rate hypothesis, which predicts that fast-growing organisms have high P content because of the preferential allocation to P-rich ribosomal RNA. In addition, we found that ontogenetic variability in NA content of the copepod Mixodiaptomus laciniatus (intra- and interstage variability) was comparable to the interspecific variability across other zooplankton species. Further, according to the metabolic theory of ecology, temperature should enhance growth rate and hence RNA demands. RNA content in zooplankton was correlated with temperature, but the relationships were nutrient-dependent, with a positive correlation in nutrient-rich ecosystems and a negative one in those with scarce nutrients. Overall our results illustrate the mechanistic connections among organismal NA content, growth rate, nutrients and temperature, contributing to the conceptual unification of metabolic and stoichiometric theories. 2014-03-06T10:00:08Z 2014-03-06T10:00:08Z 2014 info:eu-repo/semantics/article Bullejos, F.J.; et al. Nucleic Acid Content in Crustacean Zooplankton: Bridging Metabolic and Stoichiometric Predictions. Plos One, 9(1): e86493 (2014). [http://hdl.handle.net/10481/30695] 1932-6203 doi: 10.1371/journal.pone.0086493 http://hdl.handle.net/10481/30695 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Public Library of Science (PLOS)