larval growth and survival
of blue-fin sea bream, sparidentex hasta, fed on rotifer, brachionus
plicatilis, treated with different enrichments and antibiotics
T. Abu-Rezq, K. Al-Abdul-Elah, R.
Duremdez, A. Al-Marzouk, J. Al-Shimmari
Abstract:
The growth and survival of the blue-fin sea bream (Sparidentex
hasta Valenciennes) larvae after feeding on the S-type rotifer (Brachionus
plicatilis) subjected to different enrichments and antibiotics were
investigated. The highest survival (up to 32.2%, P<0.05) was obtained
when larvae were fed rotifers enriched with a mixture of algae at a ratio
2:2:1:1 (by volume) of Chlorella (25x106 cells/mL),
Nanochloropsis (20x106 cells/mL), Tetraselmis and Isochrysis
(1x106 cells/mL each), respectively, plus Super Selco and DHA
Protein Selco (half recommended dose by INVE Aquaculture NV, Belgium). No
significant difference (P>0.05) in the larval growth was observed between
different treatments. Additionally, the survival rate of larvae, which
consumed rotifers not treated with antibiotics, was significantly higher (up
to 40.0%, P<0.05) than the ones that did. Consequently, a four days
complete rotifer harvest batch culture and two times washings (before and
after 24 h treatment period) with 20 g/L water for 20 min were effective in
eliminating the bacterial colonies. Therefore, treating rotifers with
antibiotics, prior to feeding to blue-fin sea bream larvae is not conducive
to larval growth or survival.