Abstract:
In the report, the growth performance and digestive enzymes activities during early ontogeny of rock carp, and the effects of starvation treatment on these parameters were analyzed. The results showed that the growth pattern of rock carp was exponential(
y= 8.076 e
0.0261x,
R2 = 0.981), and the specific growth rate(SGR 8.29%) was much slower than most of the other fish species. The activities of trypsin, lipase, amylase and alkaline phosphatase could be detected before the mouth opening, and the activities of trypsin and lipase increased significantly during the early stage(1~10 d)(
P<0.05). While the activities of amylase and alkaline phosphatase did not change significantly during the early growth period(
P>0.05). The activities of these digestive enzymes showed a significant increased(
P<0.05) during the later growth stage(25 d), and reached at peak in 30 days, and then significantly decreased afterwards(
P<0.05). Under starvation condition, the survival rate was 0 on day 7 th after mouth opening, and the activity of protease and lipase were significantly affected by the(
P<0.05). The activities of amylase and alkaline phosphatase were decreased, however, compared with feeding groups, the change were not significant(
P>0.05). Our findings suggested that during the early growth stage, rock carp requires diets with sufficient protein and lipid, and the later growth stage of the fish larvae, a certain proportion of carbohydrate can be added as energy source.