Effects of
DHA-enriched live food on growth, survival and incidence of opercular
deformities in milkfish (Chanos chanos)
R.S.J. Gapasin, M.N. Duray-2001
Aquaculture, 193 (1-2): 49-63
Abstract:
The use of commercial enrichers to improve the
nutritional quality of live food in larviculture of milkfish was
investigated. Fish were either fed rotifers cultured on Chlorella sp. and
newly hatched Artemia nauplii (Control, Trt I) or rotifers and Artemia given
DHA enrichment diets (DHA-treated, Trt II).
Results showed survival was significantly better
(P<0.05) in the DHA-treated fish than in the untreated fish after 25-day
culture period. Although growth was not statistically different (P>0.05)
between the control and DHA-treated fish during the hatchery phase,
extensive rearing of the postlarvae (fry) in nursery ponds for another 60
days showed that DHA-treated fish exhibited significantly better (P<0.05)
growth than the untreated fish. Opercular deformities in 85-day old milkfish
juveniles were also significantly lower (P<0.05) in the DHA-treated fish
than the control. Survival after nursery culture, however, was high for both
treatments but not significantly different (P>0.05).
The lack of a viable and reliable method of mass
culturing copepods as live food in the hatchery makes the use of
off-the-shelf commercial enrichment diets for rotifers and Artemia a
practical option in the larval culture of milkfish.
(Aquaculture Department, Southeast Asian Fisheries
Development Center (SEAFDEC/AQD), 5021 Tigbauan, Iloilo, Philippines)
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