Colimitation of a freshwater herbivore by sterols and polyunsaturated fatty acids
AUTOR(ES)
Martin-Creuzburg, Dominik
FONTE
The Royal Society
RESUMO
Empirical data providing evidence for a colimitation of an herbivore by two or more essential nutrients are scarce, particularly in regard to biochemical resources. Here, a graphical model is presented, which describes the growth of an herbivore in a system with two potentially limiting resources. To verify this model, life-history experiments were conducted with the herbivore Daphnia magna feeding on the picocyanobacterium Synechococcus elongatus, which was supplemented with increasing amounts of cholesterol either in the presence or the absence of saturating amounts of eicosapentaenoic acid (EPA). For comparison, D. magna was raised on diets containing different proportions of S. elongatus and the cholesterol- and EPA-rich eukaryotic alga Nannochloropsis limnetica. Somatic and population growth of D. magna on a sterol- and EPA-deficient diet was initially constrained by the absence of sterols. With increased sterol availability, a colimitation by EPA became apparent and when the sterol requirements were met, the growth-limiting factor was shifted from a limitation by sterols to a limitation by EPA. These data imply that herbivores are frequently limited by two or more essential nutrients simultaneously. Hence, the concept of colimitation has to be incorporated into models assessing nutrient-limited growth kinetics of herbivores to accurately predict demographic changes and population dynamics.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2674483Documentos Relacionados
- Polyunsaturated fatty acids and diabetic retinopathy.
- Deficiencies of polyunsaturated fatty acids and replacement by nonessential fatty acids in plasma lipids in multiple sclerosis.
- Polyunsaturated fatty acids and nutritional quality of five freshwater fish species cultivated in the western region of Santa Catarina, Brazil
- Polyunsaturated fatty acids are potent neuroprotectors
- Interaction of polyunsaturated fatty acids with animal cells and enveloped viruses.
