Supplemental effect of vitamin A in diet on the reproductive
performance and egg quality of the Japanese flounder Paralichthys
olivaceus (T & S)
H.
Furuita, H. Tanaka, T. Yamamoto, N. Suzuki, T. Takeuchi-2003
Aquaculture
Research, 34(6): 461-468
Abstract:
This
study investigated supplemental effects of vitamin A in diet on reproduction
of Japanese flounder Paralichthys olivaceus (T & S). Broodstock
were fed either a non-supplemented diet (control diet; CD) or a vitamin
A-supplemented diet (supplemental diet; SD) 1 month before and during
the spawning season. Both dietary groups began to spawn in mid-January. At
the beginning of spawning, no notable differences were found in spawning or
egg quality between treatments. Egg production of the CD broodstock began to
decrease from mid-April and spawning stopped in late May, whereas the SD
group continued to spawn until the end of June. Buoyant egg rate of the CD
group was lower than that of the SD group throughout the spawning period.
Hatching rate was not different between the CD and SD groups. The percentage
of normal larvae in the CD group was significantly lower than in the SD
group. It is concluded that a low vitamin A content in the diet has some
negative effects on reproduction of flounder. The importance of
supplementation of vitamin A in broodstock diet of the Japanese flounder is
suggested.
(Inland Station, National Research
Institute of Aquaculture, Fisheries Research Agency, Tamaki, Mie 519-0423,
Japan. E-mail: furuita@fra.affrc.go.jp)