Inter-individual and within-brood variability in the fatty acid profiles of Norway lobster, Nephrops norvegicus (L.) embryos

The present study investigated the existence of inter-individual and within-brood variability in the fatty acid (FA) profile of developing embryos of Nephrops norvegicus. In all surveyed females (n = 5), the quantitatively most important FAs were as follows: 22:6n-3 (20.8 +/- 3.9% average of total FA +/- standard error), 18:1n-9 (19.5 +/- 2.0%), 16:0 (15.2 +/- 3.4%), 20:5n-3 (10.2 +/- 1.4%), 16:1n-7 (8.9 +/- 1.6%), and 18:1n-7 (5.7 +/- 1.3%). Differences in FA profiles of embryos in the same clutch were assessed using brooding chamber side (left and right) and pleopod (1st and 2nd, 3rd and 4th, and 5th) as predictive factors. There were no significant differences in the FA composition of embryos sampled from both sides of the brooding chamber in 4 of the 5 surveyed females. However, all females exhibited significant differences in the FA profiles of embryos sampled from different pleopods. Both saturated FA (SFA) and highly unsaturated FA (HUFA) present in developing embryos exhibited marked differences along the breeding chamber. Overall, FA reserves appeared to vary significantly within broods, which can ultimately be reflected on early larval survival. A potential cause for the within-brood variation recorded in the FA profile of developing embryos include (1) differential female investment during ovarian maturation, mainly due to variation in food quality/availability; (2) differential lipid catabolism during the incubation period of developing embryos, as a consequence of embryos position within the female's brooding chamber; or (3) differential female investment during ovarian maturation amplified by differential lipid catabolism during the incubation period.