Journal of The School of Marine Science and Technology,Vol.4 No.3
The Safety of Soybean Isoflavones in the Diet for Macrobrachium
rosenbergii and Penaeus japonicus.
Takuo KAWAMURA and Nobuhiko AKIYAMA
Abstract
The present study investigated the effects of soybean isoflavones in the diet on the sex distribution,survival and
growth of the two kinds of prawns, Macrobrachium rosenbergii and Penaeus japonicus.
A control diet (Con-d)made mainly of fish meal and three experimental diets containing glycoside soybean
isoflavones (Gly-d), aglycone soybean isoflavones (Ag-d)and estradiol 17β(E2-d)were fed to the two kinds of
prawns.
No differences were found in the sex distribution and survival rate of M. rosenbergii under the four diet feeding
conditions.In addition,the similar growth rate was found among the prawns which were given Cond-d or E2-d,while
slower growth was found in the prawns which were given Gly-d or Ag-d.
When we gave P. japonicus Con-d and the three experimental diets,the sex distribution and survival rate of the
prawns showed the same results as those of M. rosenbergii. Postlarvae of P. japonicus which were given Con-d,
Ag-d,or E2-d showed a similar growth,but they showed a less growth when Gly-d was given.In contrast,the growth
of juveniles of P. japonicus which were given Ag-d was better than that of the prawns given the other three diets.
These results indicated that marked effects on sex distribution and survival rate weren’t found when the two kinds
of prawns were given the three experimental diets,but a growth difference was observed depending on factors such
as species and developmental stage. Therefore, the safety of the diet containing soybean was suggested as long as
the amount of soybean is as much as that of general compound diets.