| Budget Amount *help |
¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 1995: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1994: ¥3,100,000 (Direct Cost: ¥3,100,000)
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| Research Abstract |
1. Gonadosomatic index (GSI) of kuruma prawn, Penaeus japonicus, fed the methanol-water soluble fraction from shortnecked clam was higher than control diet.
2. Two experiments were conducted to determine the influence of dietary lipids in semi-purified diets on the gonadal development of P.japonicus. The specific lipids that were tested were : (1) phospholipid (PL) sources phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidylcholine (PC) ; and (2), n-3 highly unsaturated fatty acids (n-3 HUFA) eicosapentaenoic acids (EPA) and docosahexaenoic acids (DHA).
In the first experiment, results showed that all three phospholipids-PE,PI and PC has similar effects (P>0.05) in promoting gonadal development of ablated P.japonicus. The prawns fed phospholipid-unsupplemented diet had significantly reduced (p<0.05) gonadal development. The phospholipid pattern of the ovaries reflected those of the phospholipid diets ; PE,PI and PC were higher in PE,PI and PC diets, respectively. Moreover, in the prawn ovaries, the total percentage of n-3 HUFA was higher in PE,PI and PC-supplemented diets than that of the PL-deficient diet.
Supplementation of EPA+DHA resulted in higher GSI compared to either EPA or DHA alone. Singly, DHA had a stronger influence on GSI than EPA.The ovarian, hepatopancreatic and muscle fatty acid composition reflected that fatty acid profile of the dietary treatments.
3. A feeding experiment was conducted to evaluate the effect of supplementing graded concentration of vitamins A and E on the ovarian development of kuruma prawn. The results showed the essentiality of supplemental vitamins A and E for increasing GSI of ablated female P.japonicus and 15mg of vitamin A/100g diet and 50mg of vitamin E/100g diet are sufficient for this purpose.
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