F. Delaunay et al., THE EFFECT OF MONOSPECIFIC ALGAL DIETS ON GROWTH AND FATTY-ACID COMPOSITION OF PECTEN-MAXIMUS (L) LARVAE, Journal of experimental marine biology and ecology, 173(2), 1993, pp. 163-179
Four batches of Pecten maxinus (L.) larvae were grown under hatchery c
onditions and fed the monospecific diets Pavlova lutheri Droop, Isochr
ysis aff. galbana Green (clone T-iso; termed Tahitian Isochrysis), Cha
etoceros calcitrans Takano and Dunaliella tertiolecta Butcher which we
re selected on their very different polyunsaturated fatty acid (PUFA)
profiles. Neutral and polar lipid PUFA compositions of larvae were inf
luenced by diets. The constant level of (n-3) PUFA in neutral lipids o
f larvae although very different in the diet indicated that neutral li
pid composition was partially controlled by the larval metabolism. Sim
ilarly, the stability of total saturated, monounsaturated and PUFA lev
els (25, 15 and 55% of total fatty acids), as well as total (n-3) PUFA
level and the preferential incorporation of the 22:6(n-3) in polar li
pids clearly indicated a metabolic regulation of the fatty acid compos
ition. The 20:4(n-6) and 22:5(n-6) acids were also preferentially inco
rporated. The accumulation of 18:3(n-3) or 20:5(n-3) with depletion of
22:6(n-3) in neutral and polar lipids of larvae fed diets with high l
evels of the first two fatty acids but little or no 22:6(n-3), indicat
ed that elongation-desaturation of dietary fatty acids was too low in
P. maximus larvae to maintain high 22:6(n-3) levels in polar lipids. T
he selective incorporation of dietary long chain PUFA into neutral and
polar lipids by acyltransferases may be the main mechanism controllin
g the fatty acid composition of larvae. These results indicate that P.
maximus larvae have essential requirements for long chain (n-3) and (
n-6) PUFA, similar to many other marine species.