Similarities between the lipid profiles of skin and liver of European Sea Bass (Dicentrarchus labrax) fed diets with different lipid content

Abstract

The specific fatty acid profile of fish can vary depending on species, age, diet and other factors. However, in general, fish are generally rich in long-chain polyunsaturated fatty acids (LC-PUFA), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Liver, skin, meat and fish mucus can contain different levels and types of fatty acids. In fact, each of these tissues can provide valuable information about the fatty acid profile of the whole fish. In order to establish a non-invasive method to assess the lipid profile of fish tissues, twenty-four European sea bass (Dicentrarchus labrax) were fed two different diets [containing different PUFAs profiles] for 30 days. Samples of cutaneous mucus, skin, flesh and liver were then obtained and their fatty acid profile was analyzed by gas chromatography. Multidimensional scaling (MDS), SIMPER procedure (similarity percentages) and permutation test (PERMANOVA) were performed. The results indicate that there are similarities in the fatty lipid profile of skin and liver, as well as between skin and liver mucus. Relationships have been observed between the fatty acid compositions of the different fish tissues, in particular between liver and skin, where linoleic acid (18:2n-6) is the most significant, which would allow the skin to be used as a proxy to infer the hepatic lipid profile, without the need to sacrifice the animals