Jp. Canavate et C. Fernandez-diaz, Pilot evaluation of freeze-dried microalgae in the mass rearing of gilthead seabream (Sparus aurata) larvae, AQUACULTURE, 193(3-4), 2001, pp. 257-269
The replacement of live microalgae by freeze-dried Nannochloropsis gaditana
(B3 strain) and Isochrysis galbana (T-ISO strain) in the mass rearing of l
arval seabream (Sparus aurata) was studied. Total substitution of live N. g
aditana by freeze-dried cells in 1 m(3) larval tanks produced similar growt
h and survival in larvae reared from first feeding until day 43 with three
different types of rotifer enrichment. Differences in growth of larvae were
only due to the type of enrichment used to feed rotifers prior to their ad
dition to larval tanks. This was regardless of the presence of live or free
ze-dried N. gaditana in the larval tanks. Specific growth rate (G) of larva
e was significantly enhanced (G = 0.106 +/- 0.001; P < 0.05) with a commerc
ial enricher compared to N. gaditana (G = 0.099 +/- 0.003) as rotifer enric
her. Feeding the rotifers with freeze-dried I. galbana produced the same la
rval growth rate (G = 0.109 +/- 0.002; P > 0.05) as the commercial enricher
, indicating the high nutritional value of these algae in a freeze-dried st
ate. Larval survival was similar in all treatments. Water quality, in terms
of dissolved oxygen and pH, was also similar in the different treatments.
Ammonia concentration was higher (P < 0.05) when freeze-dried N. gaditana w
as added to the larval tanks, but only during the first 15 days of culture,
when no water exchange was used. Nitrite did not vary (P > 0.05) during th
e first 15 days, but increased more for live N. gaditana from day 16 onward
s. Results of this study indicate the potential for a complete replacement
of live microalgae by freeze-dried microalgae throughout the whole process
of mass rearing seabream larvae. (C) 2001 Elsevier Science B.V. All rights
reserved.