Growth Rate of the Microalga
Tetraselmis suecica Changes the Biochemical Composition of Artemia
Species
J.
Fábregas, A. Otero, A. Domínguez, M. Patiño-2001
Marine Biotechnology, 3(3):256-263
Abstract:
The impact of different microalgal semicontinuous
cultures on growth and biochemical composition in the next link of the food
chain was tested using the filter feeder Artemia species as a model.
The marine microalga Tetraselmis suecica was cultured
semicontinuously with renewal rates between 10% and 50% and used to feed Artemia.
Microalgal cultures maintained with a low renewal rate that had biochemical
composition similar to that of the stationary-phase cultures commonly used
in aquaculture produced poor growth and survival and low food-conversion
efficiency compared to cultures maintained with a high renewal rate. Changes
in the renewal rate in microalgal cultures also resulted in important
changes in the gross biochemical composition of the filter feeder. The gross
biochemical composition of the Artemia resembled that of the
microalgae used as food except for total lipid content. The percentage of
protein in the organic fraction of Artemia increased from 45% to 65%
of the organic weight with increasing renewal rates in the microalgal
cultures, while the carbohydrate percentage decreased under the same
conditions. Higher renewal rates resulted in higher lipid percentages in the
microalga, but in Artemia the percentage of lipids decreased from 19%
of the organic weight with a renewal rate of 10%, to 13% with a renewal rate
of 50%. The percentage of all polyunsaturated fatty acids in Artemia,
including 20:5n-3, increased slightly with increasing renewal rates in the
microalgal cultures. Results emphasize the importance of controlling
microalgal nutritional value for the success of aquaculture food chains in
which filter feeders are involved.
(Laboratorio
de Microbiologia, Facultad de Farmacia, Universidad de Santiago, Santiago
15706, Spain, Tel.: +34-981-563100 Ext. 14944 Fax: +34-981-592210, e-mail: fabregas@usc.es)