Tham khảo tài liệu 'aquaculture part 8', khoa học tự nhiên, công nghệ sinh học phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Improving Larval Culture and Rearing Techniques on Common Snook Centropomus undecimalis 201 Influence of rotifer density on larval survival Three different rotifers densities were evaluated to determine the effect on growth and survival of common snook larvae Figure 8 . After 14 days larvae fed 5 rotifer ml diet had an average survival rate of and only 13 of all tanks stocked had live larvae. All the tanks where common snook larvae were fed 15 rotifers ml had a mean larvae survival of and 20 of tank of all tanks stocked had live larvae. In the third treatment with 30 rotifers ml 20 of the tanks had live larvae and a total average of larvae survival. No significant differences was found in larval survival between tanks fed 15 and 30 rotifer ml p . Rotifers per ml Fig. 8. Effect of 3 different rotifer densities on larval survival Increasing rotifer concentrations from 5 to 30 rotifers ml did not significantly p affect the larval length or myomere height Figure 9 . Larvae fed with 15 rotifers per ml had the highest mean length SL at mm followed by the other two treatments and mm in average respectively . Mean myomere height results were and mm respectively. Effect of alternative live food species on larval survival and growth Four different diets were used in this experiment 3 using copepods Acartia tonsa and SS type rotifers one with 100 rotifers. The diet with 75 copepods and 25 rotifers Figure 10 had the highest mean survival the second highest average larval survival occurred with the diet that had 100 rotifers . The other two diets 50 rotifers and 50 copepods and 25 copepods and 75 rotifers had similar results with mean survival. A significant difference was found between the 75 25 copepod rotifer diet and the other three diets p . No significant difference was found between the 50 50 and the 25 75 diets p . 202 Aquaculture Rotifers per ml Feed ng treatment Fig. 10. Snook .
