Nutritional properties of
the marine rotifer Brachionus plicatilis fed the freshwater microalgae
Selenastrum capricornutum
J.M. King, X.M. Liang, K.A.Rusch-2002
Journal of the World Aquaculture Society, 33(4):
478-488 (from ISI Current
Contents)
Abstract:
This study examined the effects of storage time on the fatty acid
composition of freshwater Selenastrum capricornutum algal paste under 4 C
refrigeration, the fatty acid composition of rotifers fed the fresh and
stored algal paste, and the toxicological properties of the algal paste.
Microalgae were produced in a hydraulically integrated serial turbidostat
algal reactor (HIS-TAR), harvested as a paste, refrigerated and analyzed
every 2 wk. Fresh Selenastrum capricornutum paste had almost three times
greater concentration of unsaturated fatty acids than saturated fatty acids.
Over 50% of the unsaturated fatty acids were made up of n-3 and n-6 fatty
acids. Total unsaturated, n-3 group and n-6 group fatty acids decreased (P
< 0.05) during storage, including the nutritionally important fatty acids
(C20:4n6, C20:5n3, C22:6n3). Rotifers fed 2- and 4-wk-old algal paste had a
significantly lower (P < 0.05) total unsaturated fatty acid percentage
and significantly greater (P < 0.05) total saturated fatty acids than
those fed fresh algae. There were no significant changes in the n-6 group
fatty acid level in the 4-wk-old paste feeding study or for the n-3 or n-6
groups in the 2-wk-old paste feeding study as compared to fresh algae. The
levels of the three nutritionally important fatty acids (C20:4n6, C20:50,
C22:6n3) did not differ between rotifers fed fresh and stored algae. Stored
algae did not present toxicity to rotifers and Daphnia at the normal feeding
concentration. These results indicated that the use of refrigerated
freshwater algal paste for production of rotifers results in live feed with
adequate nutritional properties for marine larviculture. This could
eliminate the costs associated with production of marine algae, which could
be replaced with freshwater algae, and may provide an alternative to
cryopreservation.
(Louisiana
State Univ., Dept. Food Sci., 111 Food Sci. Bldg., Baton Rouge, LA 70803, USA)