The Chilean scallop Argopecten purpuratus (Lamarck, 1819):: II.: manipulation of the fatty acid composition and lipid content of the eggs via lipid supplementation of the broodstock diet

Dietary supplementation with lipid emulsions during broodstock conditioning of Argopecten purpuratus was used to manipulate the fatty acid composition of the eggs. The scallops were fed a mixed algal diet either alone (Al) or supplemented with an emulsion rich in ethyl esters of docosahexaenoic acid (DHA; Al+EmDHA) or eicosapentaenoic acid (EPA; Al + EmEPA) at a concentration of 50% lipids per algal dry weight (DW). The longer induction period and the lower fecundity in scallops fed solely on algae indicated a higher food value for the lipid-supplemented diet compared to the non-supplemented diet. Lipid supplementation resulted in a significant increase of the total lipid content (mg/g DW) of the eggs. The fatty acid quality of the diet had no significant effect on the fatty acid profile of the polar lipids. However, the supplementation of the DHA-rich emulsion resulted in a significant increase of the DHA level (% of total fatty acids) in the total and neutral lipids of the eggs compared to eggs from scallops fed solely algae. The absolute DHA content (mg/g DW) increased by 47%. The EPA level in the total and neutral lipids of eggs from broodstock supplemented with EmEPA was significantly higher than in eggs from scallops fed Al + EmDHA but no significant differences were detected with eggs from the non-supplemented diet (Al). The absolute EPA concentration in eggs from scallops fed Al + EmEPA was, respectively, 19 and 17% higher than in eggs from broodstock fed, respectively, solely algae (Al) or Al + EmDHA. The results illustrated that fatty acids, supplied as emulsified ethyl esters, could be ingested and assimilated by adult A. purpuratus and were at least partially allocated to the eggs. (C) 1999 Elsevier Science Inc. All rights reserved.