Effect of arachidonic acid
levels in broodstock diet on larval and egg quality of Japanese flounder Paralichthys
olivaceus
H. Furuita, T. Yamamoto, T. Shima, N. Suzuki, T.
Takeuchi-2003
Aquaculture, 220(1-4): 725-735
Abstract:
This study investigated the effect of dietary
arachidonic acid (AA) in broodstock of Japanese flounder on subsequent egg
and larval quality. Diets with similar proximate composition and n-3 HUFA
level, but with different AA levels (0.1%, 0.6% and 1.2% of diet), were fed
to the broodstock from 3 months before and during the spawning season.
Spawning was observed from March to May. Total egg production over the
spawning season was highest in fish fed the 0.6% AA diet and lowest in fish
fed the 1.2% AA diet. All parameters measured as egg quality (percentage of
buoyant eggs, hatching rate, larval survival and normality of larvae.) were
highest in fish fed the 0.6% AA diet. AA content in eggs proportionally
increased with the dietary AA level. EPA content of polar lipids of eggs had
a negative correlation with the AA level in diets whereas the DHA content
was independent of dietary AA. The results of this study indicate that a
supplement of AA at 0.6 g/100 g diet improved the reproductive performance
of Japanese flounder, but a higher level of AA (1.2 g/100 g diet) negatively
affected both egg and larval quality due to a potential inhibitory effect on
EPA bioconversion.
(Inland Station, National Research Institute of
Aquaculture, Fisheries Research Agency, Tamaki, Mie 519-0423, Japan, e-mail:
furuita@fra.affrc.go.jp)