The aim of this plan is evaluating NNV inactivated vaccine to induce the broodstock to produce the neutralizing antibody. We wish to reduce or block the roe of NNV vertical infection. That vaccination can reduce the risk of vertical transmission of NNV of grouper broodstock. A total of 58 orange spotted grouper,Epinephelus coioides was to evaluate the immune response and protective effect use with inactivated NNV vaccine by intramuscular immune, and boosted immune at one month later. The germ cells was detected by RT-PCR and nested PCR ,results show that vaccine group was no NNV infection, Therefore, the immune broodstock contribute to block the vertical NNV infection.
The longtooth grouper (Epinephelus bruneus) with an ability to endure low temperature is a great potential new species for aquaculture in Taiwan. This species is protogynous hermaphroditic fish. Ovarian (egg diameter 160.00±44.10μm) began to grow since November, and matured to tertiary yolk globule stage (egg diameter 420.83±58.22μm) in March and egg diameter 660.00±201.10μm in May.
For TGIV which easily infected 2-inch fry stage, inactivated TGIV was used to produce active vaccine, and the vaccine was carried by artemia or adsorbed in pellet feed. Each group of 650 larvae per group were vaccine-treated with two day internal. After 3 times treatment, 20 larvae were viral challenge by i.p. Survival rate for vaccine treatd grouper can achieve 60%. The TGIV emulsion vaccine can protective for one-inched larvae in field.
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The new hybrid tilapia, bred by Freshwater Aquaculture Research Center, FRI, can be cultured to marketable size for one year only, with high male ratio, and this strain is very suitable for commercial culture. This year, 1000 thousand fry were produced and sold to 8 farmers. Additionally, the fry of Nile tilapia (Oreochromis niloticus) and Blue tilapia (Oreochromis aurea), respectively, were cultured to be selected as broodstock next year.
Cobia, Rachycentron canadium, is one of the most potential sea-cage farmed fish species in Taiwan, due to rapid growth rate, high survival rate and disease resistance. Further improvement of the rearing density of cobia in tank systems during the early stages continues to represent one of the major challenges in the consistent production of weaned fingerlings for scaling to commercial feasibility. This study succeeds to produce a lot volumeof cobia fries and the survival rate is over 10% and larval density is 517/tone-water. It concludes that the environmental factors, including light density, species and concentration of microalgae, constant water temperature, etc., are very important to cobia larvae culture.