CHANGES IN THE CONTENT OF TOTAL LIPID, LIPID CLASSES AND THEIR FATTY-ACIDS OF DEVELOPING EGGS AND UNFED LARVAE OF THE SENEGAL SOLE, SOLEN SENEGALENSIS KAUP

Total lipids, lipid classes and their associated fatty acids were quan tified in developing eggs, yolk-sac larvae and starving larvae (from d ay 1 to day 5 after hatching) of the Senegal sole, Solea senegalensis Kaup. Larvae during early development and starvation consumed about 0. 6% of its dry weight per day, mainly due to lipid catabolism. There wa s a net consumption of approximately 1.7% total lipid per day, and a n et energy utilization of 1.3 kcal g(-1) dry weight biomass day(-1), mo stly derived from lipid depletion. The overall decrease of total neutr al lipids (mainly triacylglycerols and sterol esters) was 3.4 faster t han that of total polar lipids (primarily phosphatidylcholine), with r ates of 29.2 and 8.7 mu g mg(-1) dry weight biomass day(-1), respectiv ely. There was a concomitant increase in PE, PS and phosphatidic acid during the period under study. Total saturated and total monounsaturat ed fatty acids were catabolized (primarily 16:0 and 16:1(n-7)) as ener gy substrates at rates of 7.4 and 10.9 mu g mg(-1) total lipid day(-1) , whereas total PUFAs were conserved. DHA was specifically retained in PE, whereas EPA and DHA were catabolized in PC and triacylglycerol. T otal DMA and AA contents in total lipid increased during early develop ment and starvation. The data denote a pattern of lipid metabolism dur ing early development of Senegal sole similar to that of other marine larval fish, with eggs containing high amounts of total lipids (presen ce of oil globule/s), from temperate waters and with short development al periods; the pattern contrasts with fish larvae from eggs of cold w ater fish species that contain low levels of total lipids (lack of oil globule/s) and have long developmental periods.