| The resource shortage of glass eel has become the bottleneck problem of Chinese eel industry. The glass eel resource of Anguilla japonica has declined year by year, while the glass eel of A. anguilla was export restricted, so the most important way to solve this problem is to develop and disseminate new species of eel before eel artificial propagation. A. marmorata has rich glass eel resource with high economic value, thus has great development potential. But it still need more in-depth research on larvae breeding and nutritional requirements of juvenile eel in order to realize the large-scale production of A. marmorata.A. Desalting forms and opening diet of the glass eel of A. marmorataThree desalting forms(A-drop 1ppt/d and stay 7 days;B-drop 2ppt every two days, 3times, then drop 1ppt at 7th day; C-drop 1.4ppt/d at the first 4 days then drop 0.5ppt/d at the last 3days) were conducted to evaluate the effect of different desalting forms on survival rate of the glass eel of A. marmorata,. The results showed that the survival rate of them were all above 95% and there was no significant difference between each other(P<0.05). Five different initial diets(blood worm, Surimi, Tubifex hattai, brine shrimp and artificial diet) were fed the glass eel of A. marmorata for 6 weeks. The results showed that the suitability was in the order: brine shrimp(29) blood worm(29) Tubifex hattai(29) artificial diet(29) Surimi. And the SGR, WGR and SR of Anguilla marmorata in brine shrimp group was significantly higher than the other groups with its SR reaching 100%(P<0.05).B. Effects of dietary taurine on growth performance, digestive enzyme activity, serum parameters and muscle amino acids of A. marmorataA 14-weeks feeding trial was conducted to evaluate the effect of dietary taurine on growth performance, digestive enzyme activity, serum parameters and muscle amino acids of A. marmorata with initial body weight 85.95 g. Five experimental diets were formulated with the addition of 0%, 0.20%, 0.40%, 0.60% and0.80% taurine, thus contained 0.708%, 0.908%, 1.108%, 1.308% and 1.508% taurine in fact(named as D1, D2, D3, D4 and D5). The results showed that with the increasing of dietary taurine, the final weight of the fish firstly increased, then deceased and peaked in D4 group. The weight gain rate(WGR) and specific growth rate(SGR) in D4 group were significantly higher than those in D1 and D2 groups(P<0.05). Crude Protein, total lipid and ash contents in muscle were increased and moisture was decreased with the dietary taurine level increasing, and the crude protein content in D3 group was significantly higher than that in D1 group(P<0.05). The fish fed the diets with 1.108%-1.308% taurine displayed significantly higher amylase activity and protease activity in stomach and intestine and higher lipase activity in liver. The TG, TC and TP firstly increased, then deceased, while TG peaked in D4 group and was significantly lower than D1, D2 and D3 group(P<0.05). But TG, TP and ALB exhibited no significant difference(P<0.05). The TEAA and TAA firstly increased, then deceased, while the TEAA in D4 group was significantly higher than D1, the TAA in D3 and D4 groups was significantly higher than D1(P<0.05).The Asp, Glu, Val, Leu, Lys reached the highest in D4 group, which were significantly higher than D1(P<0.05). It is therefore suggested that the optimum dietary taurine level for A. marmorata is 1.308%. |
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