The importance of dietary HUFAs for fecundity and HUFA content in the harpacticoid, Tisbe holothuriae Humes

Fatty acid distribution was investigated in adult and naupliar Tisbe holothuriae, reared on 3 different diets with n−3 HUFA contents constituting 0.1, 1.5 and and 12.8% DW, respectively. Whereas certain characteristic differences in the fatty acid profiles of the 3 diets used clearly were reflected in the copepods, the long-chain n−3 HUFAs 20:5 n−3 and 22:6 n−3 were present in consistently high amounts. When reared on a diet with negligible contents of n−3 HUFAs, but high in 18:3n−3, T. holothuriae appeared to be able to synthesize these fatty acids at significant rates. Also, the reproductive performance of T. holothuriae on the 3 diets was studied. Of the two microalgal diets studied, the one with the high n−3 HUFA content resulted in considerably higher sustained naupliar productivity during the first 15 days of the production period of the cultures. However, no difference in brood size (first two broods) was found.