EFFECTS OF BROODSTOCK DIETS ON FATTY-ACID COMPOSITION, SURVIVAL AND GROWTH-RATES IN LARVAE OF THE EUROPEAN FLAT OYSTER, OSTREA-EDULIS

Thirteen broods of Ostrea edulis larvae from four specific broodstock treatments were analysed for growth, mortality and fatty acid composit ion. Larvae from different broodstock treatments, reared under the sam e standard hatchery conditions with identical diets for 12 days, showe d different growth rates but mortality was similar. Growth rates range d from 1.4 to 5.9 mu m per day. Growth rate was significantly related to the content of total polyunsaturated fatty acids (PUFAs) and 22:6 n -3 fatty acids in newly released larvae. The content of 22:6 n-3 from different broodstocks explained 50% of the variation in growth rate am ong broods. However the content of PUFA and the 22:6 n-3 fatty acid di d not differ among broodstock treatments. It is suggested that a fast assay for essential PUFA like 22:6 n-3 may significantly improve manag ement of commercial bivalve hatcheries. (C) 1997 Elsevier Science B.V.