5种光色对牙鲆(Paralichthys olivaceus)幼鱼生长、生化及基因表达的影响

Growth、biochemical responses and gene expression of juvenile Paralichthys olivaceus to five light colors

中文关键词: 牙鲆  光色  生长  酶活  激素  基因

英文关键词: Paralichthys olivaceus  light color  growth  Enzyme activity  Hormone  gene

中文摘要:

      牙鲆（Paralichthys olivaceus）具有体型大、成长速度快、肉质优良、营养价值丰富及洄游距离短等特点，是重要的海水增养殖经济物种。由于牙鲆工厂化养殖模式的集约化程度高和环境可控性强，该模式被广泛应用。在该模式下，养殖车间通常采用人工照明来满足养殖需求。但不同光色环境对水生生物的生长、生理生化过程及应激反应有一定的抑制或促进作用。同一光谱对不同发育阶段的同种鱼类产生的影响亦有不同。目前不同光色对牙鲆幼鱼的影响未见报道，因此本文选取了450尾体质优良且体型均匀的牙鲆幼鱼作为研究对象，设置了5种LED光谱参数，分别为红光（λ 625~630 nm）、黄光（λ 570~575 nm）、蓝光（λ 450~455 nm）和绿光（λ 525~530 nm），以及全光谱光（λ 380~780 nm）作为对照组。水温控制在（18.0±1.0）℃，光照周期为12 L:12 D，光强设置为（250 ± 20）mW/m2。研究5种不同光色对牙鲆幼鱼生长、酶活、激素及基因表达的影响，旨在为牙鲆幼鱼工厂化养殖光色选择提供理论支撑。结果显示：蓝光组和绿光组牙鲆幼鱼的增重率和特定生长率显著高于其他组（P＜0.05）。红光组牙鲆幼鱼生长激素含量最低为10.68±0.61 ng/mL，显著低于其他组（P＜0.05），而皮质醇含量最高为1487.44±54.42 pg/mL，显著高于其他组（P＜0.05）；蓝光组牙鲆幼鱼生长激素含量最高为20.74±1.52 ng/mL，显著高于其他组（P＜0.05）。绿光组牙鲆幼鱼胃淀粉酶活力显著高于红光组和对照组（P＜0.05）；红光组牙鲆幼鱼的胃纤维素酶活力显著低于对照组（P＜0.05）；红光组牙鲆幼鱼肠纤维素酶活力显著低于其他组（P＜0.05）。红光组牙鲆幼鱼血清CAT活力显著低于其他组（P＜0.05），肝脏CAT活力显著低于对照组（P＜0.05）；各实验组牙鲆幼鱼肝脏SOD活力差异不显著（P＞0.05）。红光组牙鲆幼鱼肝脏SOD基因的相对表达量显著低于黄光组（P＜0.05），但与其他组差异不显著；红光组牙鲆幼鱼肝脏CAT基因的相对表达量最低，且显著低于其他组（P＜0.05），黄光组牙鲆幼鱼肝脏CAT基因的相对表达量最高，且显著高于其他组（P＜0.05），蓝光组、绿光组和对照组牙鲆幼鱼CAT基因的相对表达量差异不显著。结果表明，蓝光和绿光下养殖对牙鲆幼鱼生长具有明显促进作用，在红光下，牙鲆幼鱼持续处于应激状态，抗氧化能力和消化能力均减弱。该研究结果为提高牙鲆幼鱼室内工厂化养殖效能提供理论依据，对工厂化牙鲆幼鱼绿色健康养殖具有重要的推动作用。

英文摘要:

      Paralichthys olivaceus has become an economically important target species for marine aquaculture due to its large size, rapid growth rate, excellent meat quality, rich nutritional value and short-distance migratory habit. The industrial farming model has been widely used due to its high degree of intensification and environmental controllability. In this mode, artificial lighting is commonly used in factory farming to meet the farming needs. Compared with the traditional artificial lighting of straight tube fluorescent lamps or compact fluorescent lamps, LED lamps not only have the advantages of energy saving and environmental protection, long service life, low heat generation and high photoelectric conversion efficiency, but also have the ability to accurately regulate the spectrum and intensity of light according to the demand, which has been rapidly promoted in the factory farming. Different light-colour environments has a certain degree of inhibitory or promotional effects on the growth, physiological and biochemical processes, and stress responses of aquatic organisms. In this study, A total of 450 individuals with good body condition and uniform body size were selected, with a mean body mass of (309.66 ± 32.73) g and an initial total length of (28.67 ± 2.66) cm. Five LED spectral parameters were set, which were red (λ 625~630 nm), yellow (λ 570~575 nm), blue (λ 450~455 nm) and green (λ 525~530 nm), and full spectrum (λ380~780 nm) as the control group. water temperature was controlled at (18.0±1.0)℃, photoperiod was 12L:12D. The light intensity was set at (250 ± 20) mW/m2. Five different light colors on the growth, enzyme activity, hormone and gene expression of juvenile Paralichthys olivaceus were studied. The enzyme activities included two antioxidant enzymes, SOD and CAT , and two digestive enzymes, amylase and fibrillase, the hormones included growth hormone and cortisol, and the genes were mainly SOD and CAT. The aim was to provide theoretical support for the selection of light color for juvenile Paralichthys olivaceus in factory farming. The results showed that the weight gain rate and specific growth rate of juvenile Paralichthys olivaceus in the blue light groups and green light groups were significantly higher than the others (P < 0.05). The growth hormone content of juvenile Paralichthys olivaceus in the red light group was the lowest at 10.68±0.61 ng/mL, which was significantly lower than that of other groups (P < 0.05), while the cortisol content was the highest at 1487.44±54.42 pg/mL, which was significantly higher than that of other groups (P < 0.05). The growth hormone content of juvenile Paralichthys olivaceus in the blue light group was the highest at 20.74±1.52 ng/mL, which was significantly higher than that of other groups (P < 0.05). The gastric amylase activity of juvenile Paralichthys olivaceus in the green light group was significantly higher than that of the red light group and the control group (P < 0.05). The gastric cellulase activity of juvenile Paralichthys olivaceus in the red light group was significantly lower than that of the control group (P < 0.05). The intestinal cellulase activity of juvenile Paralichthys olivaceus in the red light group was significantly lower than that of the other groups (P < 0.05). In the red light, the CAT activity in the serum of juvenile Paralichthys olivaceus in the red light group was significantly lower than that of other groups (P < 0.05), and the liver CAT activity was significantly lower than that of the control group (P < 0.05). The differences in liver SOD activity of juvenile Paralichthys olivaceus in each light colour group were not significant (P > 0.05). The relative expression of liver SOD gene of juvenile Paralichthys olivaceus in the red light group was significantly lower than that in the yellow light group (P < 0.05), but the difference with other groups was not significant; the relative expression of CAT genes in the liver of juvenile Paralichthys olivaceus in the red light group was the lowest and significantly lower than that in the other groups (P < 0.05), the relative expression of liver CAT gene of juvenile Paralichthys olivaceus in the yellow light group was the highest and significantly higher than that in the other groups (P < 0.05), and the relative expression of CAT gene of juvenile Paralichthys olivaceus in the blue light group, green light group and control group was not significant. The results showed that blue and green light culture significantly affected the growth of juvenile Paralichthys olivaceus, while red light continuously stressed juvenile Paralichthys olivaceus weakening their antioxidant and digestive capacities. The results provide a theoretical basis for improving indoor factory aquaculture efficacy of juvenile Paralichthys olivaceus and promote green healthy factory aquaculture of juvenile Paralichthys olivaceus in factories.