INFLUENCE OF THE EPA/DHA RATIO IN ROTIFERS ON GILTHEAD SEABREAM ( SPARUS AURATA) LARVAL DEVELOPMENT

C. Rodriguez, J.A. Perez, M. Diaz, M.S. Izquierdo, H.

Fernandez-Palacios, A. Lorenzo-1997

Aquaculture, 150: 77-89

Abstract:

A feeding experiment was carried out to investigate the influence of

the eicosapentaenoic acid (EPA, 20:5n-3) to docosahexaenoic acid

(DHA, 22:6n-3) ratio (EPA/DHA) on 17-day-old Sparus aurata larval

development. Larvae were fed rotifers (Brachionus plicatilis)

enriched with four different lipid emulsions containing the same

amount of total n-3 highly unsaturated fatty acids (n-3 HUFA) but

different EPA/DHA ratios. The different EPA/DHA ratios of the

emulsions gave rise to different ratios in the enriched rotifers.

Furthermore, increments of the EPA/DHA ratio in rotifers produced a

decrease in larval growth performance, so that larvae fed rotifers

containing the highest EPA/DHA ratio showed the poorest growth

rate. The analysis of fatty acids from larvae showed that there was a

significant linear relationship between EPA/DHA ratio in their total

polar lipids (TPL) and larval growth. At the same time, when the

EPA/DHA ratio increased in rotifers, there was an increase in total

n-3 HUFA in larvae total neutral lipid (TNL), which was mainly due

to the accumulation of EPA.

Results obtained in the present study suggest that for the same level

of total n-3 HUFA, larval growth performance can be improved by a

decrease in EPA/DHA ratio in rotifers, indicating the importance of

DHA during the first days of S. aurata larval development.

(Departamento de Biologia Animal, Universidad de La Laguna,

38270 La Laguna, Tenerife, Canary Islands, Spain)

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