The fatty acid composition
of Octopus vulgaris paralarvae reared with live and inert food:
deviation from their natural fatty acid profile
J.C.
Navarro, R. Villanueva-2003
Aquaculture, 219(4): 613-631
Abstract:
The fatty acids of the mature ovary, late eggs and
wild juveniles of Octopus vulgaris were analysed to establish, in
accordance with the published data on the fatty acid composition of
hatchlings, a theoretical framework of the ideal fatty acid profile, i.e.
the "natural" fatty acid profile, during the early life of the
species. The time course variation of the fatty acid composition of
paralarvae reared in cultures fed enriched Artemia nauplii on their
own, or supplemented with encapsulated microdiets, was also analysed and
compared. The fatty acid composition of the cultured planktonic paralarvae
was chemometrically related to that of the wild benthic juveniles by means
of a multivariate discriminant analysis. Irrespective of the dietary
treatment, the artificial feeding produced distinct lipid and fatty acid
profiles as compared to the "natural" one. The influence of the
fatty acid profile of Artemia seems clearly reflected in the cultured
O. vulgaris paralarvae. The effect of the fatty acid composition of
food was evident in the paralarvae after 10 days of feeding and remained
essentially unchanged during the experimental period up to 30 days. The
total lipid of the cultured animals increased notably, as did the levels of
monounsaturated fatty acids, to the detriment of polyunsaturated fatty acids
(PUFA) and, particularly, docosahexaenoic acid (DHA). Poor growth and high
mortality seemed to result from a nutritional imbalance in the fatty acid
profile (i.e. DHA/eicosapentaenoic acid (EPA) ratio) produced by the
artificial feeding, suggesting also that the microdiet was inefficiently
digested and/or assimilated. Wild juveniles tend to lose lipids as they
increase in weight. Possible causes are discussed.
(Instituto
de Acuicultura de Torre de la Sal (CSIC), E-12595, Ribera de Cabanes,
Castellón, Spain, e-mail : jcnavarro@iats.csic.es)