环境光色对工业化养殖豹纹鳃棘鲈幼鱼生长、肤色及生理指标的影响

为探究环境光色对工业化养殖豹纹鳃棘鲈(Plectropomus leopardus)幼鱼生长、肤色和生理指标的影响,本试验设计了红色光、蓝色光、黑暗和昼夜4种养殖光照环境处理,进行豹纹鳃棘鲈幼鱼(64.2g±1.1g)94 d动物实验及其相关指标检测。结果表明:1)试验鱼增重率,昼夜组较黑暗组和红光组分别显著和极显著提高28.6%和39.2%(P0.05,P0.01),与蓝光组差异不显著;而蓝光组比红光组显著提高31.2%(P0.05)。2)试验鱼皮肤胡萝卜素含量,昼夜组分别显著高于蓝光组和黑暗组45.7%和68.5%(P0.05),与红光组的差异不显著。同时新发现,各处理组试验鱼皮肤胡萝卜素和黑色素含量出现增减同时进行,但增减量前者较大后者较小的"同步异幅"现象。3)昼夜组试验鱼胃蛋白酶活性较其他组显著提高48.0%~88.5%(P0.05),血清SOD和LZM活力极显著提高20.4%~39.7%和140.4%~161.2%(P0.01);蓝光组试验鱼胰蛋白酶活力显著高于红光组和昼夜组(P0.05);红光组试验鱼Na~+,K~+-ATP酶活力极显著高于蓝光组和黑暗组(P0.01)。总之,豹纹鳃棘鲈幼鱼在昼夜组光照下,生长、肤色及生理等指标都表现出显著优势;蓝色光提高蛋白质消化能力、促进生长;红色光提高皮肤胡萝卜素含量和吸收能力;"同步异幅"新发现,对调控和优化鱼类肤色具有重要价值。

Effects of light color on growth, skin color, and physiological indices of juvenile Plectropomus leopardus in a recirculating aquaculture system

Plectropomus leopardushas high economic value and vast market prospects because of its nutritional and delicious flesh and appealing body color. This experiment investigated the effects of light color on growth, skin color, and physiological indices of juvenileP. leopardus in a recirculating aquaculture system (RAS). The trial employed a single factor design of four light colors (red, blue, dark, and day-night) to raise juvenileP. leop-ardus(body weight, 64.2 g±1.1 g) for 94 d. As a result, the weight gain rate of fish in the day-night group in-creased by 28.6% and 39.2% compared with that in the dark and red light groups (P<0.05,P<0.01), but no differ-ence was observed compared with the blue light group (P>0.05). The weight gain rate in the blue light group in-creased by 31.2% compared with that in the red light group (P<0.05). Skin carotene content of fish in the day-night group exceeded that in the blue and dark light groups by 45.7% and 68.5%, respectively (P<0.05), but no difference was observed compared with the red light group (P<0.05). Skin carotene and melanin contents of fish increased and decreased at the same time, but by different amounts in the four treatments. Therefore, we de-fined this phenomenon as “synchronous but different magnitude”. Pepsin activity of fish in the day-night group increased by 48.0%–88.5% (P<0.05) compared with that in the other groups. Fish in the day-night group had bet-ter immunity, assuperoxide dismutase and lysozyme activities were significantly higher than those in the other groups (P<0.01), whereas malondialdehyde level was lower than that in the dark and red groups (P<0.05,P<0.01). Na+, K+-ATPase activity increased by a mean of 78.1% in the day-night and red light groups (P<0.01). Trypsin activity was significantly higher in the blue light group than that in the red and day-night light groups by 34.3% and 21.8%, respectively (P<0.05). In conclusion, our data demonstrate that juvenileP. leopardusunder day-night light had better growth, skin color, and physiological performance than those held under the other conditions. Blue light improved protein digestive ability and growth, and red light increased carotene content and nutrition absorp-tion by fish. The “synchronous but different magnitude” phenomenon helped regulate and optimize fish skin color. These results suggest that the light color juvenileP. leopardus are exposed to in a RAS should be considered to optimize growth and skin color.