Vizcaíno A J, Rodiles A, López G, Sáez M I, Herrera M, Hachero I, Martínez T F, Cerón-García M C, Alarcón F Javier
Departamento de Biología y Geología, Escuela Superior de Ingeniería, Universidad de Almería, La Cañada de San Urbano, 04120, Almería, Spain.
School of Biological Sciences, Plymouth University, Plymouth, UK.
Fish Physiol Biochem. 2018 Apr;44(2):661-677. doi: 10.1007/s10695-018-0462-8. Epub 2018 Jan 21.
Senegalese sole is one of the most promising fish species cultivated in the Southern European countries. This study was aimed at assessing the effects of microalgae biomass added to diets for Senegalese sole juveniles on fish growing and condition status. Three isoproteic (52%) and isolipidic (10%) were formulated containing 15% Tisochrysis lutea (TISO), Nannochloropsis gaditana (NAN), or Scenedesmus almeriensis (SCE) biomass, respectively. An experimental microalgae-free diet (CT) and a commercial diet (COM) were used as controls. Fish were fed at 3% of their body weight for 85 days. Final body weight of fish fed microalgae-supplemented diets did not differ from group fed CT diet. Fish-fed CT, TISO, NAN, and SCE showed higher growth performance and nutrient utilization figures than specimen-fed COM diet. The highest carcass lipid content was found in COM group (141 g kg), and no differences were observed in body protein content. Ash was significantly higher in TISO, NAN, and SCE groups compared to fish-fed CT. Muscle EPA and DHA contents were not modified owing to the different dietary treatments. The n3/n6 and EPA/DHA ratios in muscle were similar in all the experimental groups. The quantification of digestive proteolytic activities did not differ among experimental groups, although differences in the protease pattern in digestive extracts by zymography were revealed in those fish fed on COM diet. Both α-amylase activity in the intestinal lumen and leucine aminopeptidase in the intestinal tissue were significantly lower in COM fish. Specimens fed on SCE diet showed a higher leucine aminopeptidase activity associated to the intestinal tissue compared to NAN-fed fish (0.40 and 0.25 U g tissue, respectively). The ultrastructural study revealed that the dietary inclusion of algal biomass, especially T. lutea and N. gaditana, had a positive impact on the absorptive capacity of the intestinal mucosa. The highest values for the parameters microvilli length and microvilli absorption surface were observed in fish fed on NAN diet (1.99 μm and 45.93 μm, respectively). Even though further studies aimed at optimizing commercial formulas for Senegalese sole are required prior to any large-scale practical utilization, the results obtained clearly suggest the potential of microalgae as dietary ingredients for this fish species.
塞内加尔鳎是南欧国家养殖的最具潜力的鱼类之一。本研究旨在评估添加微藻生物质的饲料对塞内加尔鳎幼鱼生长和健康状况的影响。配制了三种等蛋白（52%）和等脂（10%）的饲料，分别含有15%的金藻（TISO）、纤细角毛藻（NAN）或阿尔梅里亚栅藻（SCE）生物质。一种不含微藻的实验饲料（CT）和一种商业饲料（COM）用作对照。以鱼体重的3%投喂85天。投喂添加微藻饲料的鱼的终末体重与投喂CT饲料的组没有差异。投喂CT、TISO、NAN和SCE的鱼比投喂COM饲料的鱼表现出更高的生长性能和营养利用率。COM组的鱼体脂肪含量最高（141 g/kg），鱼体蛋白质含量没有差异。与投喂CT的鱼相比，TISO、NAN和SCE组的灰分显著更高。不同的饲料处理对肌肉中二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）的含量没有影响。所有实验组肌肉中的n3/n6和EPA/DHA比值相似。消化蛋白水解活性的定量分析在实验组之间没有差异，尽管通过酶谱分析发现投喂COM饲料的鱼的消化提取物中的蛋白酶模式存在差异。COM组鱼的肠腔中α-淀粉酶活性和肠组织中的亮氨酸氨肽酶活性均显著较低。与投喂NAN饲料的鱼相比，投喂SCE饲料的鱼的肠组织中亮氨酸氨肽酶活性更高（分别为0.40和0.25 U/g组织）。超微结构研究表明，饲料中添加藻类生物质，尤其是金藻和纤细角毛藻，对肠黏膜的吸收能力有积极影响。投喂NAN饲料的鱼的微绒毛长度和微绒毛吸收表面积参数值最高（分别为1.99μm和45.93μm）。尽管在进行任何大规模实际应用之前，还需要进一步研究以优化塞内加尔鳎的商业配方，但所获得的结果清楚地表明了微藻作为这种鱼类饲料成分的潜力。
