Department of Fisheries, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
Fish Physiol Biochem. 2010 Sep;36(3):555-564. doi: 10.1007/s10695-009-9326-6. Epub 2009 May 21.
This study was carried out to examine the effect of Artemia urmiana nauplii enriched with HUFA, and vitamins C and E on stress tolerance, hematocrit, and biochemical parameters of great sturgeon, Huso huso juveniles. Cod liver oil (EPA 18% and DHA 12%), ascorbyl-6-palmitate and alpha-tocopherol acetate were used as lipid, and vitamin C and E sources, respectively. Beluga juveniles at the stage of first feeding (69.7 +/- 5.9 mg body weight) were randomly divided into five treatments and three tanks were assigned to each diet. All fish groups were fed non-enriched Artemia for the initial 5 days and then fed enriched Artemia for 7 days. Juveniles were fed with Artemia enriched with HUFA + 20% vitamin C (C group); HUFA + 20% vitamin E-enriched Artemia nauplii (E group); HUFA + 20% vitamin C + 20% vitamin E (C and E group); HUFA without vitamins (HUFA) and non-enriched Artemia (control). After the period of enrichment, Juveniles were fed with Daphnia sp. from the 13th to the 40th day. At day 40, the fish were transferred directly from fresh water (0.5 ppt) to brackish water (6 ppt for 4 days and 12 ppt for 2 days) and warm water (from 27 to 33 degrees C) to evaluate juvenile resistance to salinity and thermal shocks. Moreover, all treatments were separately exposed to freshwater in tanks with the same capacity as used for osmotic and thermal tests (as fresh water control). The addition of vitamins C, E, and C + E to HUFA significantly increased fish resistance to 12 ppt salinity and temperature stress tests, whereas survival was not significantly different among challenges at 6 ppt. There was no significant difference in the hematocrit index under stress conditions. Enrichment had significant influence on plasma Na(+) level in the C group on the 4th day at 6 ppt. Na(+) and Ca(2+) concentrations in C, E, and C and E groups on the 1st day at 12 ppt, and Ca(2+) level in E group on the 2nd day at 12 ppt were lower than the other groups. The glucose level in the C and C and E groups was lower than the other treatments on the 1st day at 12 ppt and the 2nd day at 33 degrees C. Regardless of Artemia enrichment, plasma ions (Na(+), K(+), Ca(2+), and Mg(2+)) and glucose concentrations in fish exposed to salinity stress tests were higher than fish in fresh water. Glucose concentration in plasma also increased after 2 days at 33 degrees C. Although most of our results were not significantly different, the use of vitamins C, E, and HUFA in Artemia enrichment can improve Juveniles tolerance under stress conditions, and regardless of enrichment, these data show that beluga juveniles are partly sensitive to high salinity and temperature.
本研究旨在探讨富含 HUFA、维生素 C 和 E 的卤虫无节幼体对施氏鲟幼鱼应激耐受性、血细胞比容和生化参数的影响。使用鳕鱼肝油（EPA18%和 DHA12%）、抗坏血酸棕榈酸酯和α-生育酚醋酸酯分别作为脂质和维生素 C、E 的来源。贝鲁加幼鱼在初次摄食阶段（69.7±5.9mg 体重），随机分为 5 组，每组 3 个鱼缸。所有鱼组均在最初的 5 天内喂食未富集的卤虫，然后喂食富集的卤虫 7 天。幼鱼被喂食富含 HUFA+20%维生素 C 的卤虫（C 组）；富含 HUFA+20%维生素 E 的卤虫无节幼体（E 组）；富含 HUFA+20%维生素 C+20%维生素 E（C 和 E 组）；不含维生素的 HUFA（HUFA）和未富集的卤虫（对照组）。富集期结束后，幼鱼从第 13 天到第 40 天喂食水蚤。第 40 天，鱼直接从淡水（0.5ppt）转移到半咸水（6ppt 持续 4 天，12ppt 持续 2 天）和温水（27 至 33 摄氏度），以评估幼鱼对盐度和热冲击的抵抗力。此外，所有处理组均在与渗透和热测试相同容量的水箱中单独暴露于淡水（作为淡水对照）。HUFA 中添加维生素 C、E 和 C+E 显著提高了鱼类对 12ppt 盐度和温度应激测试的抵抗力，而在 6ppt 挑战中，存活率没有显著差异。在应激条件下，血细胞比容指数没有显著差异。在第 4 天的 6ppt 时，C 组的血浆 Na+水平在富集后显著升高。在第 1 天的 12ppt 时，C、E 和 C 和 E 组的血浆 Na+和 Ca2+浓度以及 E 组的第 2 天的 Ca2+浓度均低于其他组。在第 1 天的 12ppt 和第 2 天的 33 摄氏度时，C 和 C 和 E 组的葡萄糖水平均低于其他处理组。无论是否进行卤虫富集，暴露于盐度应激测试的鱼类的血浆离子（Na+、K+、Ca2+和 Mg2+）和葡萄糖浓度均高于淡水鱼类。在 33 摄氏度下 2 天后，血浆中的葡萄糖浓度也有所增加。尽管我们的大多数结果没有显著差异，但在卤虫富集中使用维生素 C、E 和 HUFA 可以提高幼鱼的应激耐受性，并且无论是否进行富集，这些数据都表明贝鲁加幼鱼对高盐度和高温有一定的敏感性。
