Marine lipids
18:1 (n-7) despite Skeletonema costatum mainly supplied 16:1 (n-7). This
result is consistent with those of Whyte (1988) who showed that juvenile oysters synthensed 18:1 (n-7) when their diet contains significant
proportions of 16:1 (n-7) but no 18:1 (n-7).
Although Skeletonema costatum contains a high proportion of C16 PUFAs,
these fatty acids were poorly accumulated into lipids of oysters. These
fatty acids are typical of Skeletonema costatum and are not usually found
in lipids from oysters. This strongly supported the hypothesis that
oysters are able to select dietary fatty acids limiting the absorption
and/or the esterification of non-usual fatty acids into their lipids.
Conclusion
Supplying Skeletonema costatum largely improves condition index and could
be a useful practice to fatten oysters for Christmas and New Year celebrations. However, it induces large changes in chemical composition
of oysters increasing sharply glycogen content and modifying fatty acid
composition of total lipids. So, before generalizing this practice, sensory analyses must be carried out to be sure that these chemical changes
have not adverse effects on sensory attributes of oysters.
Acknowledgments
We gratefully acknowledge Mrs C. Marzin for carrying out the analysis, Mr Nourry
and Mr Palvadeau for carrying out the fattening of oysters.
Bibliographic references
Ackman R.G., Jangaard P.M., Hoyle R.J., Brockerhoff H., 1964. Origin
of marine fatty acids. I. Analyses of the fatty acids produced by the
diatom Skeletonema costatum. J. Fish. Res. Bd Can., 21, 747-756.6.
Baud J.-P., Bacher C., 1990. Use of saline ground water for intensive
rearing Ruditapes philippinarum juvenile in a nursery system. Aquaculture, 88, 157-178.
Baud J.-P., Haure J., Garnier J., 1990. Effets de l’apport de phytoplancton (Skeletonema costatum) sur la croissance et les variations de
la composition biochimique de la palourde japonaise Ruditapesphilippinarum cultivée en marais. Océanis, 16, 391-408.
Baud J.-P., Cardinal M., Haure J., 1995. Improvement of oyster market
quality with a new fattening procedure. In: Proceedings of International Conference Aqtiaculture Europe’95, August 1995, Trondheim, Norway, 231-232.
Bergé J.-P., Gouygou J.-P., Dubacq J.-P., Durand P., 1995. Reassessment
of lipid composition of the diatom Skeletonema costatum. Phytochemistry, 39, 1017-1021.
120
18:1 (n-7) despite Skeletonema costatum mainly supplied 16:1 (n-7). This
result is consistent with those of Whyte (1988) who showed that juvenile oysters synthensed 18:1 (n-7) when their diet contains significant
proportions of 16:1 (n-7) but no 18:1 (n-7).
Although Skeletonema costatum contains a high proportion of C16 PUFAs,
these fatty acids were poorly accumulated into lipids of oysters. These
fatty acids are typical of Skeletonema costatum and are not usually found
in lipids from oysters. This strongly supported the hypothesis that
oysters are able to select dietary fatty acids limiting the absorption
and/or the esterification of non-usual fatty acids into their lipids.
Conclusion
Supplying Skeletonema costatum largely improves condition index and could
be a useful practice to fatten oysters for Christmas and New Year celebrations. However, it induces large changes in chemical composition
of oysters increasing sharply glycogen content and modifying fatty acid
composition of total lipids. So, before generalizing this practice, sensory analyses must be carried out to be sure that these chemical changes
have not adverse effects on sensory attributes of oysters.
Acknowledgments
We gratefully acknowledge Mrs C. Marzin for carrying out the analysis, Mr Nourry
and Mr Palvadeau for carrying out the fattening of oysters.
Bibliographic references
Ackman R.G., Jangaard P.M., Hoyle R.J., Brockerhoff H., 1964. Origin
of marine fatty acids. I. Analyses of the fatty acids produced by the
diatom Skeletonema costatum. J. Fish. Res. Bd Can., 21, 747-756.6.
Baud J.-P., Bacher C., 1990. Use of saline ground water for intensive
rearing Ruditapes philippinarum juvenile in a nursery system. Aquaculture, 88, 157-178.
Baud J.-P., Haure J., Garnier J., 1990. Effets de l’apport de phytoplancton (Skeletonema costatum) sur la croissance et les variations de
la composition biochimique de la palourde japonaise Ruditapesphilippinarum cultivée en marais. Océanis, 16, 391-408.
Baud J.-P., Cardinal M., Haure J., 1995. Improvement of oyster market
quality with a new fattening procedure. In: Proceedings of International Conference Aqtiaculture Europe’95, August 1995, Trondheim, Norway, 231-232.
Bergé J.-P., Gouygou J.-P., Dubacq J.-P., Durand P., 1995. Reassessment
of lipid composition of the diatom Skeletonema costatum. Phytochemistry, 39, 1017-1021.
120