Serum lipoproteins, lipid classes and fatty acid characterization in Brown Skua (Stercorarius antarcticus) durign breeding

IBÁÑEZ, A.E.; PASQUEVICH, M.Y.; GRAÑA GRILLI, M.; FERNANDEZ, M.; BERG, G.; HERAS, H.; MONTALTI, D.

Jornada; XVIII Jornadas Anuales Multidisciplinarias Sociedad Argentina de Biología; 2016

In migratory birds, circulating lipids provide most of the energy during breeding. This energy source is mobilized through the blood by lipoproteins to be used by other tissues. After migration, food sources with high-energy fats may be important to birds preparing for breeding. In this work we studied the circulating lipid amount, classes and transport in adult Brown skuas serum during the breeding cycle. Blood samples were obtained in three different moments: In (incubation), Pi (after egg hatching) and Pii (during chick rearing). Lipoprotein levels (VLDL, LDL and HDL) were determined by agarose (2%) electrophoresis. Lipids were extracted by Bligh & Dyer method and characterized by Thin Layer Cromatography (TLC) and total fatty acids (FA) were analyzed by gas chromatography. Differences in lipoproteins levels were observed, with higher values of VLDL during In and higher levels of HDL in Pii stage. Whereas no differences in total lipid amount were observed, differences in total FA relative amounts through the reproductive stages were found. Moreover, a slight difference in saturated (18:0 and 22:0), monounsaturated (18:1(n9)) and polyunsaturated (18:2(n6)) FA levels was observed. Altoghether, the differences observed may be related to the nutritional status as well as to the foraging behaviour of Brown skua during breeding.