Supplementation of arachidonic acid rich oil in European sea bass juveniles (Dicentrarchus labrax) diets: Effects on growth performance, tissue fatty acid profile and lipid metabolism

Citation

Torrecillas S, Betancor M, Caballero MJ, Rivero F, Robaina L, Izquierdo MS & Montero D (2018) Supplementation of arachidonic acid rich oil in European sea bass juveniles (Dicentrarchus labrax) diets: Effects on growth performance, tissue fatty acid profile and lipid metabolism. Fish Physiology and Biochemistry, 44 (1), pp. 283-300. https://doi.org/10.1007/s10695-017-0433-5

Abstract
The aim of this study was to evaluate the effects of increasing dietary arachidonic acid (ARA) levels (from 1 up to 6 % of total fatty acids) on European sea bass (Dicentrarchus labrax) juveniles growth performance, tissue fatty acid profile, liver morphology as well as long chain polyunsaturated fatty acids (LC-PUFA) biosynthesis, triglyceride and cholesterol synthesis and lipid transport. A diet with total fish oil (FO) replacement and defatted fish meal (FM) containing a 0.1 g ARA g-1 diet was added to the experimental design as a negative control diet. Dietary ARA inclusion levels below 0.2 g ARA g-1 diet significantly worsened growth even only 30 days after the start of the feeding trial, whereas dietary ARA had no effect on fish survival. Liver, muscle and whole body fatty acid profile mainly reflected dietary contents and ARA content increased accordingly with ARA dietary levels. Tissue eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) levels were positively correlated among them. Hepatic lipid vacuolization increased with reduced dietary ARA levels. Expressions of fatty acyl desaturase 2 and 3-hydroxy-3-methylglutaryl-coenzyme genes were up-regulated in fish fed the negative control diet compared to the rest of the dietary treatments denoting the influence of ARA on lipid metabolism. Results obtained highlight the need to include adequate n-6 levels and not only n-3 LC-PUFA levels in European sea bass diets. Keywords: Dicentrarchus labrax, arachidonic acid, growth performance, tissue fatty acid profile, lipid metabolism

Keywords
Dicentrarchus labrax; arachidonic acid; growth performance; tissue fatty acid profile; lipid metabolism

Journal
Fish Physiology and Biochemistry: Volume 44, Issue 1

People

Dr Monica Betancor

Associate Professor, Institute of Aquaculture