Replacement of a large portion of fish oil by vegetable oils does not affect lipogenesis, lipid transport and tissue lipid uptake in European seabass (Dicentrarchus labrax L.) Nadège Richard a , Gabriel Mourente b , Sadasivam Kaushik a , Geneviève Corraze a, ⁎ a UMR Nutrition Aquaculture Génomique, INRA Pôle Hydrobiologie, 64310 Saint Pée-sur-Nivelle, France b Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain Received 24 April 2006; received in revised form 17 July 2006; accepted 17 July 2006 Abstract In order to investigate the impact of dietary lipid sources on mechanisms involved in lipid deposition, three groups of European seabass fingerlings with average initial body weight of 5.2 ± 1.0 g were fed three diets differing only by lipid source. These diets were: 100% anchovy oil (diet A), 40% anchovy oil–60% mix of vegetable oils (35% linseed, 15% palm, 10% rapeseed) (diet B) and 40% anchovy oil–60% mix of vegetable oils (24% linseed, 12% palm, 24% rapeseed) (diet C). After 64 weeks of rearing, when seabass reached the size of 160 g, the activity of lipogenic enzymes (fatty acid synthetase, glucose-6-phosphate dehydrogenase and malic enzyme) in liver and of lipoprotein lipase (LPL) in perivisceral adipose tissue, liver and white muscle were measured. Transport of lipid by lipoproteins was examined by determining plasma lipid composition and lipoprotein classes. Dietary oil source did not modify growth performance or lipid content of flesh and liver of seabass. Replacement of 60% of fish oil by the two mixtures of vegetable oils had no significant effect on hepatic lipogenesis and activity of LPL in liver and adipose tissue. Activity of LPL in white muscle was decreased in fish fed diet C compared to those fed diets A and B. Diets containing the mixture of vegetable oils led to lowered plasma, VLDL and LDL cholesterol levels compared to diet A. It is concluded that replacing 60% of fish oil by the two mixtures of vegetable oils in the feeds of European seabass fingerlings until they reach the size of 160 g has no marked effect on growth performance, lipogenesis and tissue lipid uptake but has a hypocholesterolemic effect. © 2006 Elsevier B.V. All rights reserved. Keywords: Fish oil; Lipogenesis; Lipoprotein lipase; Lipoproteins; European seabass; Vegetable oils Aquaculture 261 (2006) 1077 – 1087 www.elsevier.com/locate/aqua-online Abbreviations: AA, arachidonic acid (20:4n-6); CPO, crude palm oil; DHA, docosahexaenoic acid (22:6n-3); EPA, eicosapentaenoic acid (20:5n-3); FAS, fatty acid synthetase; FO, fish oil; G6PD, glucose-6-phosphate dehydrogenase; HDL, high density lipoprotein; LA, linoleic acid (18:2n-6); LDL, low density lipoprotein; LNA, α-linolenic acid (18:3n-3); LO, linseed oil; LPL, lipoprotein lipase; ME, malic enzyme; OA, oleic acid (18:1n-9); OO, olive oil; PUFA, polyunsaturated fatty acid; RO, rapeseed oil; SO, soybean oil; TAG, triacylglycerol; VLDL, very low density lipoproteins; VO, vegetable oil. ⁎ Corresponding author. Tel.: +33 5 59 51 59 89; fax: +33 5 59 54 51 52. E-mail address: corraze@st-pee.inra.fr (G. Corraze). 0044-8486/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.aquaculture.2006.07.021