effect of
enriched live feeds on survival and growth rates in larval korean rockfish,
sebastes schlegeli hilgendorf
S.H. Cho, S.B. Hur, J.-Y. Jo-2001
Aquaculture Research, 32(3): 199-208
Abstract:
High mortality frequently occurs in larval mass
production of Korean rockfish. Sebastes schlegeli Hilgendorf. Nutritional
deficiencies in live feeds, rotifers and Artemia nauplii, fed to larvae
could be a reason. A series of experiments was carried out to evaluate the
effect of nutritional enrichment of live feeds by ω-yeast, Spirulina
powder and Super SelcoTM on survival and growth rates in rockfish
larvae. Preference of rockfish larvae for the live feeds was determined by
analysis f stomach contents. In addition, the effect of green water produced
by the use of Chlorella ellipsoidea and Spirulina powder on the growth
performance of larvae was evaluated. Larvae fed rotifers that were
nutritionally enriched with both Super Selco and Spirulina together
exhibited improved growth and survival rates. Larvae fed Artemia nauplii
nutritionally enriched with Spirulina powder showed significantly higher
survival than larvae fed Artemia nauplii without enrichment. When larvae
were fed rotifers, Artemia nauplii or the mixture of rotifers and Artemia
nauplii, the second and last group showed significantly higher survival than
the first group. Fatty acid
composition in live feeds was improved by enrichment of ω-yeast and
larvae fed this feed showed higher survival and growth rates compared with
larvae fed non-enriched feeds. No positive effect of green water in the tank
produced with C. ellipsoidea or Spirulina powder was observed on survival
and growth rates for larvae fed nutritionally enriched rotifers with Super
Selco and Spirulina powder. However, when the larvae were fed Artemia
nauplii that were nutritionally enriched with ω-yeast and Spirulina
powder, green water obtained by adding Spirulina powder to the tanks
resulted in significantly higher growth rates of larvae than was obtained by
adding C. ellipsoidea.
(Department of Aquaculture, Pukyong National
University, Pusan 608-737, Korea)