The Influences Of Light Color On Growth, Physiological And Biochemical Indices Of Juvenile Plectropomus Leopardus

Plectropomus leopardus is delicious and nutritious. In addition, its apparance is so gorgeous. Therefore, the exploitation of plectropomus leopardus has a broad market prospect in China, with high economic value. In recent years,the industrial recirculating aquaculture technology for plectropomus leopardus has been realized and popularized. Nevertheless, so far there has been little research on the influences of light color on physiological and biochemical systems. 900 plectropomus leopardus(body weight 92.92 ± 4.05 g,body length19.67 ± 1.26 cm)are randomly divided into five groups. Each group is divided into three parallel tests with 60 fish. The fish are cultured in 5 different light colors:dark, white, red, yellow and green, with 120 d. The experiment in the white color is regarded as the control group. The light intensity, light period and other conditions are consistent. After the experiments, the growth performances, digestive enzyme activities, serum biochemical parameters, immunohistochemical enzyme indicators and so on are measured and analyzed statistically. Then, the experimental results are obtained as follows:1. The influences of light color on the growth performances of juvenile plectropomus leopardusThere are significant differences between the survival rates of juvenile plectropomus leopardus in 5 light colors:the survival rate in the white group is less than 50% and significantly lower than that in other light color groups; the survival rate in the red group is significantly lower than that in the dark and green group. In the meanwhile, the survival rate in the green group is highest, close to 90%. Full-length of juvenile plectropomus leopardus in the green group is significantly larger than that in other groups and there are significant differences between the body weights in different color groups; there are significant differences between body weights in green and other groups, and there are also significant differences between red, dark and white, yellow groups. The differences between splenosomatic indexes and head-kindey indexes are little, while the differences between hepatosomatic indexes are significant. There are significant differences between hepatosomatic indexes in white and red groups, and there are also significant differences between red,dark and green groups. According to the growth, survival and other indexes, it’s concluded that the green light is the most suitable light for plectropomus leopardus to grow and survive, while the white light is inappropriate.2. The influences of light color on the digestive enzyme activities of juvenile plectropomus leopardusThe phenomenon that the AMS activity of plectropomus leopardus is very low and the AMS activity in the stomach does not exist is found. The activity of pepsin in the stomach is only expressed in stomach, while the activity of trypsin is high-level expressed in the intestine, stomach, liver and pancreas. The activity arrangement of LPS from lowest to highest in organs is stomach, hepatopancreas and intestine. Light colors have an effect on the digestive enzyme activity and the effects are significantly different between different light colors: the AMS activity in the green group is lowest while highest in the white group; green group can significantly increase the activity of protease and LPS. In conclusion, white light can increase AMS activity, while green light can improve LPS and protease activity.3. The influences of light color on serum biochemical parameters of juvenile plectropomus leopardusThe Glu level of juvenile plectropomus in the white group is significantly lower than that in other four groups,while there is no significant difference between the Glu levels in other four groups. The LDLC level in the red group is significantly lower than that in other groups. There are significant differences between the TP levels in dark, yellow, white, red and green group. The ALB level in the white group is significantly lower than that in other groups, and the ALB level in the yellow group is significantly lower than that in the dark group. There are significant differences between the GLB levels in the dark and white group. The ALT level, AST level and LDH level in the white group are highest, and the CREA level and BUN level in the white group are also higher than those in other groups. There is no significant difference between Ca2+, P3+, Na+, K+ levels in the juvenile plectropomus leopardus muscles in five light color groups,except of the Mg2+ level.4. The influences of light colors on immunohistochemical enzyme of juvenile plectropomus leopardusThere is no significant difference between the AKP levels of juvenile plectropomus leopardus in five light color groups. The AKP level in the white and dark group is slightly lower than that in the red and green group. The ACP level in the muscle is low and the differences between in five groups are little(P> 0.05). The activity of the ACP in the gill and kidney in the white and green group is higher than that in the red group. The activity of the ACP in the liver in the yellow group is highest, while lowest in the white group. Light colors have a significant influence on the SOD activity. The SOD activity in the red is highest and significantly higher than that in the dark group. The CAT activity in the muscle is not detected, while there are significant differences between the CAT activities in other organs, with irregular effects of light colors on the activities. In a word, the SOD activity is relatively stable, white and dark could reduce the immune activity, while yellow and green could increase immune activity.