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排序方式: 共有1512条查询结果,搜索用时 15 毫秒
981.
南美白对虾室外育苗的初步试验 总被引:1,自引:0,他引:1
在4个室外水泥池和2个室内水泥池进行南美白对虾育苗试验,室外池总育苗水体为40 0m3,室内池总育苗水体为20 0m3。直接在室外育苗池培养单胞藻;白天日照时间为8h以上,光照强度为500~8000lx;室外育苗池共放入南美白对虾无节幼体600万尾,培育至体长1 0cm的虾苗,出苗354 4万尾,总成活率为59 1%。室外育出的虾苗规格整齐,体质强壮;比室内池育苗的时间缩短3~4d。 相似文献
982.
The effect of dietary vitamin K (phylloquinone and menadione) levels on the vertebral formation in mummichog Fundulus heteroclitus 总被引:3,自引:0,他引:3
Miho Udagawa 《Fisheries Science》2001,67(1):104-109
SUMMARY: The effect of different dosages of vitamin K, either as phylloquinone or menadione sodium bisulfite (MSB), on vertebrae formation during growth of mummichog Fundulus heteroclitus was investigated. Diets without vitamin K caused a significantly higher incidence of bone deformity in fish than diets supplemented with MSB or phylloquinone ( P < 0.01). These results indicate that vitamin K is essential for mummichog. A massive dose of MSB caused a high incidence of bone deformity compared with a lower dose, while an increased dose of phylloquinone brought about no significant difference in deformity incidence. The vertebral deformity was significantly higher ( P < 0.01) in fish fed a vitamin K-free diet (Control Group) and MSB-supplemented diet (Group MSB25) compared to fish fed a phylloquinone-supplemented diet (Group PK1). These results indicate that phylloquinone is more suitable than MSB as a vitamin K source in fish feed. 相似文献
983.
S.H. ABDEL RAHMAN 《Aquaculture Nutrition》1996,2(3):151-155
Four types of food were tested to determine their effects on the growth and survival of larvae of the penaeid shrimp Penaeus japonicus Bate. The food types were live cells of Candida utilis (yeast), freeze-dried Candida utilis, microparticulate diet, and microencapsulated diet (commercial product). The diatom Chaetoceros gracilis was fed to larvae as a control. Two sets of experiments were carried out; the first was run in outdoor 1.5 ton tanks, and the second in indoor 1.2 ton tanks. In the outdoor experiment, the best survival and growth from nauplius to postlarva stage were obtained using microparticulate diet. During the first week of culture, freeze-dried Candida utilis resulted in the highest growth and survival among examined diets, but both factors dropped dramatically after the mysis stage. In the indoor experiment, the best growth and survival were obtained using live cells of Candida utilis from nauplius stage to end of mysis stage followed by brine shrimp. Tested diets were analysed for their contents of crude protein, total lipids, total carbohydrates, amino acid profiles and fatty acid contents. 相似文献
984.
赤点石斑鱼早期仔鱼轮虫日摄食量的研究 总被引:7,自引:2,他引:7
赤点石斑鱼早期仔鱼轮虫日摄食量的研究王涵生(福建省水产研究所,厦门361005)关键词赤点石斑鱼,仔鱼,轮虫,日摄食量STUDIESONTHEDAILYCONSUMEDNUMBERSOFROTIFERFEDBYTHEEARLYLARVAEOFEPIN... 相似文献
985.
A.I. Campa-Crdova A. Luna-Gonzlez F. Ascencio E. Corts-Jacinto C.J. Cceres-Martínez 《Aquaculture (Amsterdam, Netherlands)》2006,260(1-4):145-150
This study focused on determining the effects of antibiotics on microalgae used as food for scallop larvae. Six different dose levels of chloramphenicol, erythromycin, and furazolidone were added to cultures of Isochrysis galbana and Chaetoceros gracilis. An in vivo experiment was subsequently conducted to determine the effect of chloramphenicol and erythromycin on larval survival of the Pacific calico scallop Argopecten ventricosus in tanks and on the population of its associated bacteria. Results showed that growth of I. galbana was not significantly affected by chloramphenicol or erythromycin at the test doses of 0.5, 1.0, 3.0, 6.0, 9.0, and 12.0 mg/l. C. gracilis was significantly sensitive to erythromycin and chloramphenicol at doses higher than 0.5 and 3.0 mg/l, respectively. Furazolidone inhibited the growth of both I. galbana and C. gracilis at all test doses. Results showed that exposure of scallop larvae to a dose of 6 mg/l chloramphenicol or erythromycin did not significantly affect growth of I. galbana, significantly enhanced survival of the scallop larvae, and inhibited the growth of Vibrio spp. in tanks. This study demonstrated the adverse effect of chloramphenicol, erythromycin and furazolidone on I. galbana and C. gracilis microalgae but the positive effect on survival of the scallop larvae, decreasing associated bacterial population. 相似文献
986.
987.
海水仔稚鱼早期阶段氨基酸的营养生理研究进展 总被引:6,自引:0,他引:6
深海海鱼鱼卵中的游离氨基酸占鱼卵总氨基酸含量的近50%(干重),游离氨基酸库中的游离氨基酸似乎是卵黄蛋白的水解产物。仔鱼吸收卵黄内源营养的过程中,游离氨基酸库中的游离氨基酸逐渐减少,到仔鱼开始摄食时,库中的游离氨基酸已近枯竭,游离氨基酸不仅是代谢能源,而且是体蛋白合成的基本原料,仔鱼开始摄食后,氨基酸作为分解代谢的重要物质,可能有高达60%的能量由氨基酸提供,由于仔稚鱼的生长主要是通过合成蛋白质增加鱼体的重量,加之仔稚鱼的生长速度很高,因此,仔稚鱼需要其饲料中有较高的氨基酸含量。仔鱼开始摄食后,其消化系统对蛋白质的水解和吸收能力较弱,海水仔稚鱼的早期阶段,仔鱼的肠道对游离氨基酸的吸收要高于对多肽和蛋白质中氨基酸的吸收,仔鱼开始摄食后,由浮游生物获得大量的游离氨基酸,用微粒饲料培育仔稚鱼,微脂粒技术可能是向饲料中添加游离氨基酸的实用技术。 相似文献
988.
通过研究近年来国内外学者关于甲壳动物幼体消化酶方面的研究现状,发现目前已测定出甲壳动物幼体消化酶的种类主要有:蛋白酶、胰蛋白酶、羧肽酶A、羧肽酶B、氨肽酶、胶原酶、弹性蛋白酶、胃蛋白酶、糜蛋白酶、酯酶、脂肪酶、淀粉酶、纤维素酶、几丁质酶、麦芽糖酶、蔗糖酶、昆布多糖酶等种类,初步归纳了甲壳动物幼体主要消化酶的分子量、最适pH和最适温度;分析了幼体发育过程中消化酶活力变化模式以及与食性的关系,并采用淀粉酶/蛋白酶活力(A/P)比值或淀粉酶/类胰蛋白酶(A/T)比值作为甲壳动物幼体的食性指标;观察了幼体消化器官的发育,阐明幼体消化酶的合成与分泌不仅由遗传控制、中肠腺发育程度等因子决定,而且还与饲料的营养水平有关,提出采用幼体消化酶对饲料组成的适应性研究幼体营养需求的新途径.[中国水产科学,2006,13(3):492-501] 相似文献
989.
Turbot larvae were exposed to dilutions of the water soluble fraction (WSF) of crude oil (1–25%), in a laboratory flow-through system. Whole body immunoreactive cortisol (IRC) content of premetamorphic 345 degree C day and early metamorphosing 450 degree C day larvae (23 and 30 days post hatch, respectively) was elevated when exposed to 25% WSF for 6 h, but the lower WSF concentrations did not induce IRC elevations. Larvae of 450 degree C days exposed to WSF for 6 h and then left in clean sea water for 24 h showed recovery of IRC, whilst the IRC content of 450 degree C day larvae exposed to WSF for 30 h remained elevated. Whole body thyroxine content of 345 degree C day larvae exposed to 25% WSF for 6 h was significantly elevated, which may have implications for larval development/metamorphosis. However, whole body triiodothyronine content of these larvae was not altered by WSF-exposure. Furthermore, larvae of 450 degree C days, WSF-exposed for 6 h or 30 h showed no thyroidal disturbance. Larvae of 345 degree C days exhibited significantly elevated whole body adrenaline and noradrenaline content after exposure for 6 h to 25% WSF; however, more diluted WSF did not influence adrenaline or noradrenaline content. These studies have demonstrated that larvae of 345 and 450 degree C days can successfully mount endocrine stress responses but that environmentally realistic concentrations of petroleum hydrocarbons do not induce these responses. 相似文献
990.
Essential fatty acid requirements of cultured marine fish larvae 总被引:14,自引:1,他引:14
M. S. IZQUIERDO 《Aquaculture Nutrition》1996,2(4):183-191
Feeding of marine fish larvae is, in most cases, limited to the administration of two species of live prey. This reduction in the range of food available for the cultured larvae may occasionally lead to nutritional imbalances or deficiencies. A large amount of research has been recently devoted to the study of the essential fatty acid requirements of marine fish larvae. Studies on the biochemical composition of developing eggs and larvae, as well as the comparison of the patterns of loss and conservation during starvation, pointed out the importance of n-3 HUFA and arachidonic acid as essential fatty acids for larvae of marine fish. The biochemical composition of marine fish larvae, in terms of lipid content and fatty acid composition of total and polar lipids, is modified by dietary levels of essential fatty acids. Larval growth, survival and activity have also been reported to be affected by dietary levels of essential fatty acids. In addition, some pathological signs, such as hydrops or abnormal pigmentation, have been related to essential fatty acid deficiency in these fish. Based on these effects, the essential fatty acid requirements of marine larval fish have been reported to range between 0.3 and 55 g kg?1 n-3 HUFA on a dry weight basis, suggesting that quantitative requirements of fish larvae may differ from those of juveniles or adults. But quantitative requirements for larvae of the same species reported by various authors are often contradictory. These differences are discussed in relation to the dietary lipid content, ratio 20:5n-3/22:6n-3 and culture conditions used. 相似文献