Influence of one selected Tisochrysis lutea strain rich in lipids on Crassostrea gigas larval development and biochemical composition

• Published in: Aquaculture Nutrition
• Main Authors: Da Costa, F., Petton, Bruno, Mingant, Christian, Bougaran, Gael, Rouxel, Catherine, Quere, Claudie, Wikfors, G. H., Soudant, P., Robert, Rene
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley-blackwell 2016
• Subjects: larvae; lipids; oyster; Tisochrysis lutea; Crassostrea gigas
• Online Access: https://archimer.ifremer.fr/doc/00251/36258/36063.pdf; https://doi.org/10.1111/anu.12301; https://archimer.ifremer.fr/doc/00251/36258/

Effects of a remarkably high overall lipid Tisochrysis lutea strain (T+) upon gross biochemical composition, fatty acid (FA), sterol and lipid class composition of Crassostrea gigas larvae were evaluated and compared with a normal strain of Tisochrysis lutea (T) and the diatom Chaetoceros neogracile (Cg). In a first experiment, the influence of different single diets (T, T+ and Cg) and a bispecific diet (TCg) was studied, whereas, effects of monospecific diets (T and T+) and bispecific diets (TCg and T+Cg) were evaluated in a second experiment. The strain T+ was very rich in triglycerides (TAG: 93–95% of total neutral lipids), saturated FA (45%), monounsaturated FA (31–33%) and total fatty acids (4.0–4.7 pg cell−1). Larval oyster survival and growth rate were positively correlated with 18:1n-7 and 20:1n-7, in storage lipids (SL), and negatively related to 14:0, 18:1n-9, 20:1n-9, 20:4n-6 and trans-22-dehydrocholesterol in membrane lipids (ML). Surprisingly, only the essential fatty acid 20:5n-3 in SL was correlated positively with larval survival. Correlations suggest that physiological disruption by overabundance of TAG, FFA and certain fatty acids in larvae fed T+ was largely responsible for the poor performance of these larvae. ‘High-lipid’ strains of microalgae, without regard to qualitative lipid composition, do not always improve bivalve larval performance.