S. Garrido, E. Saiz, J. Peters, P. Re, P. Alvarez, U. Cotano, D.L. Herrero, A. Martinez de Murguia, X. Irigoien
Journal of Experimental Marine Biology and Ecology, 434-435, 1624, (2012)
Experiments were conducted during the summer of 2008 and 2009 to study the growth of early post yolk-sac European anchovy (Engraulis encrasicolus,
Linnaeus, 1758) larvae reared under different food regimes. The fatty
acid composition was used to assess nutritional condition of the larvae.
Prey items used in the experiments were Gymnodinium sanguineum, Brachionus plicatilis and nauplii of the copepods Acartia grani and Euterpina acutifrons.
Food type and concentration affected the growth of the larvae. Mixed
diets composed of rotifers and copepod nauplii at high concentration
resulted in higher anchovy larvae growth rates in comparison with
single-prey diets using either rotifers or copepod nauplii. The addition
of the dinoflagellate G. sanguineum (25–50 cells ml− 1) to the prey offered did not enhance significantly larval growth. Highest growth rates of anchovy larvae (0.28 mm d− 1) were obtained using high concentrations of a mixed diet, particularly the combination of rotifers and A. grani
nauplii. Fatty acid composition at hatch was similar to the composition
observed in the field, but during larvae ontogeny there was a marked
decrease in the contribution of polyunsaturated fatty acids such as EPA
(eicosapentaenoic acid) and DHA (docosahexaenoic acid). Such difference
reflects the high requirements of these PUFA for larvae development, and
suggests that the food offered failed to fulfill the larvae nutritional
requirements. The growth rates obtained in our experiments were,
overall, in the lower range of those observed in natural conditions.
Taking into considerations the fact that larvae in the field are
expected to encounter lower prey concentrations, we discuss the reasons
for such disagreement.