Essential lipids in aquatic food webs: requirements and eco-physiological constraints
A dietary deficiency in essential lipids has serious physiological and ecological consequences for invertebrate consumers. Polyunsaturated fatty acids (PUFA) and sterols are indispensable structural components of eukaryotic cell membranes and serve as precursors for a number of bioactive molecules, such as eicosanoids and ecdysteroids. Eicosanoids are known to modulate reproduction and immunity while ecdysteroids are involved in the process of molting. PUFA are involved in the so-called homeoviscous adaptation of membranes to varying temperatures and the dietary PUFA supply may thus affect the ability of ectothermic animals to cope with low environmental temperatures. PUFA-derived eicosanoids have been shown to influence invertebrate immune responses and there is evidence that the dietary PUFA supply can affect the outcome of parasite-host interactions and the susceptibility to pathogens. Sterol auxotrophy is widespread among invertebrates. In contrast to animals, which predominantly contain cholesterol, plants and especially algae contain a great diversity of phytosterols. Consequently, herbivorous invertebrates need to metabolize dietary phytosterols to cholesterol to cover their physiological demands. Dietary phytosterols, however, differ substantially in their potential to support growth and reproduction of invertebrates. Investigating the physiological constraints associated with an inadequate dietary lipid supply is thus crucial for understanding the performance of animals under various environmental conditions. Aim of this talk is to highlight recent advances in biochemical food quality research and to point out gaps in knowledge and new avenues for future research.
Host: Justyna Wolinska