G. Oie, P. Makridis, K. I. Reitan, Y. Olsen-1997
Aquaculture, 153: 103-122
Abstract:
The effect of three different rotifer enrichments was examined on growth, survival, pigmentation and viability of first feeding turbot larvae. The diets differed in rotifer content of protein, lipid and ratio of protein/lipid. The diets were fed to turbot with or without algae (Isochrysis galbana) added to the larval tanks. The turbot larvae were fed rotifers for 10 days and thereafter the same Artemia diet was fed to all treatments for the rest of the experimental period. Growth and survival of fish larvae were higher in tanks containing algae than in tanks where no algae were added. Independent of algal addition, the highest growth rate and survival was obtained by feeding rotifers containing the highest protein content. Larvae reared in greenwater consumed higher numbers of rotifers during the stagnant period than larvae kept in clearwater conditions, while analysis of the larval gut contents showed lower rotifer numbers in the gut of larvae reared in greenwater conditions. This must imply longer residence time of the food in the larval gut, and presumably also higher digestion and assimilation efficiencies of larvae maintained without algae than in larvae maintained with algae. Calculation of protein and carbon conversion efficiency showed higher utilization in larvae maintained without algae (18-28% for protein, 12-19% for carbon) than in larvae maintained with algae (6-9% for protein, 4-7% for carbon). No significant differences in pigmentation rate and stress sensitivity were observed among the larvae of the various treatments.
(SINTEF Applied Chemistry, Center of Aquaculture, N-7034 Trondheim, Norway)
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