3. Results
3.1. Diets composition
The proximate compositions of the two diets showed significant differences for all the measured parameters. Moisture (F = 422; P = 0.002), ash (F = 225; P = 0.004) and carbohydrate (F = 140; P = 0.007) contents were higher in the Kelp diet while its lipid (F = 680; P = 0.001), protein (F = 57,6; P = 0.02) and energy (F = 1265; P = 0.001) contents were lower (Table 3). Moreover, multivariate analysis revealed that there was a significant difference in overall FA signature of the diets (P = 0.01), FA compositions are shown in Table 3. Monounsaturated FAs were the most represented group in the Pellet diet, although 18:2n − 6 was the most abundant FA in this diet accounting for the vast majority of n − 6 PUFA. In the Kelp diet, n − 3 PUFA was the most abundant class with EPA and 18:4n − 3 being the most represented FA. ARA and EPA contents were significantly higher in Kelp than in the Pellet diet (ARA: F = 70.3 P = 0.01; EPA: F = 63.2 P = 0.01) while no DHA was found in Kelp. Therefore, only individuals fed with the Pellet diet received dietary DHA input. The differences in EPA, DHA and ARA contents between the diets were reflected in the relative proportion of these LC-PUFAs with the EPA/ARA ratio being significantly higher in the Pellet diet than in Kelp, while the absence of DHA in the Kelp diet did not allow for DHA/EPA ratio calculation for this diet.