Utilization of lipids by Dentex dentex L-(Osteichthyes, Sparidae) larvae during lecitotrophia and subsequent starvation

Total lipids, lipid classes and their associated fatty acids were measured in developing eggs, yolksac larvae and starving larvae (from fertilized egg to day 9 after hatch) of the common dentex Dentex dentex (L., 1758). The larvae of common dentex during lecitotrophia and subsequent starvation consumed 1.6 mu g of total lipid per larvae per day. The overall decrease was mainly due to utilization of the major neutral lipids, TAG and SE (0.5 and 0.6 mu g larvae(-1) day(-1), respectively) which was 3.4-fold greater than that of the the major phosphoglycerides (primarily PC by 0.2 mu g larvae(-1) day(-1)). There was net synthesis/conservation of PE during the first half of the study period before it decreased rapidly (0.2 mu g larvae(-1) day(-1)) during the second half. PUFAs were principally catabolized (468.6 ng larvae(-1) day(-1)), primarily 22:6(n-3), 20:5(n-3) and 20:4(n-6) (221.8, 58.5 and 12.1 ng larvae(-1) day(-1), respectively). Saturated and monounsaturated fatty acids were also utilized (227.2 and 256.7 ng larvae(-1) day(-1), respectively), principally 16:0 and 18:1(n-9) that were both consumed at 149.8 and 156.7 ng larvae(-1) day(-1), respectively. The rank order of utilization of fatty acids (ng larvae(-1) day(-1)) by D. dentex larvae from total lipids, PC and TAG coincided with the order of abundance of the different fatty acids in the respective lipid fractions. However, in PE, the most abundant fatty acid, DHA, was relatively conserved and 16:0, the second most abundant fatty acid, was catabolized to the greatest extent. D. dentex showed a pattern of lipid metabolism during early development similar to that of marine larval fish from temperate waters whose eggs contain high levels of total lipids, including an oil globule, and which preferentially utilize neutral lipids as the primary energy source.