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保水宁是有益微生物的活菌制剂,经过活化后施于水中,可改善养殖水体水质和池塘底质。保水宁主要作用有以下几方面: 一、迅速降解有机物,改善水质条件 保水宁成品状态为干粉剂,细胞处于休眠期,一进入养殖水体即能活化,并迅速以倍数繁殖成为养殖水体中的优势种群,需氧代谢与厌氧代谢并存,特别是在十分缺氧的老化 相似文献
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研究了麦饭石和过氧化氢作为水质净化剂对水体中水化因子的调控作用和效果,结果表明:双氧水能有效去除水中有机物,且基本无残留;麦饭石对养殖水体具有双向调节酸碱度的作用,能有效降低水体中的有害物质含量,麦饭石的一次使用量为50 mg/L,一次效应为8天左右。随着使用量的提高,水体中的NH_4~ -N和NO_2~--N的浓度降低的效果更为明显,且效用时间更长,尤其是在水质恶化时其作用更为明显。 相似文献
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光合细菌添加剂是一种活菌添加剂,已在河北、山东等地大规模推广使用,给渔业生产带来了可观的经济效益,在池塘对虾养殖生产上效益更为显著。光合细菌属厌气性光能自养型细菌,它能在无氧条件下利用光能,吸收利用水体中的有机物质,迅速繁殖起来,从而强化水中和池底有机物质的循环,消除水中有害物质,提高水体代谢机能,增加水中营养,使水体保持良性生态平衡。因此,在养殖水域中使用光合细菌添加剂,既能净化水质,增加水中溶氧,有效地控制泛塘,又能增加水体中的浮游生物量, 相似文献
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池塘养殖试验证实微生态制剂能有效提高水体溶解氧含量、调节水中三氮和有效磷的含量以及水体pH值，并降低水中BOD5，并且能显著增强养殖对象的免疫力，降低其发病率，具有提高养殖产量的作用。 相似文献
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从女山湖水体的物理和化学特性看，水质呈中性，属软水，有一定的缓冲能力；水中溶氧丰富，有利于水中有机质的分解和利用，促进营养盐类的再生，控制水质恶化；水中营养盐类较为丰富，有利于微生物和水生植物的生长是水产养殖的良好水体。 相似文献
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随着鳜鱼集约化生产的发展 ,鳜鱼赖以生存的水环境引起人们的高度重视 ,水体质量的好坏直接影响鳜鱼养殖的成败 ,因此 ,了解和研究鳜鱼水体环境及其影响 ,就能有目的地调控水体质量 ,满足鳜鱼生长发育的需要。鳜鱼与其它鱼类相比 ,既有共性又有其特殊性 ,鳜鱼对水质的要求较高。根据我们历年来养殖成鳜的经验和对水质的研究 ,以及对周边主养鳜鱼池水质调查 ,总结出几种主要水质指标对鳜鱼的影响及其改良措施 ,现归纳如下。１池塘几种主要水质指标对鳜鱼的影响１．１悬浮固体水中悬浮固体是形成水浑浊度的主要因素 ,悬浮颗粒越大 ,硬度越大 ,… 相似文献
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水质恶化是水产动物集约化养殖过程中养殖水体经常出现的问题,也是影响水产动物健康的主要原因之一。特别是近几年国内水产品需求的增加以及对外虾、蟹、贝类、鳗等水产品出口旺盛,我国的水产养殖面积及集约化程度均取到了长足的发展,但伴随而来的水质恶化事件也是屡见不鲜,其中以氨氮、亚硝酸盐等水化学因子浓度超标最为突出,也最为常见。目前养殖过程中用于改善养殖水体的水质改良剂以化学制剂居多,比如大分子聚合物、强氧化剂等,但其短效性的缺点限制了该类制剂的大规模应用或慎用。而良好的微生态制剂在改善水质方面则能弥补化学制剂的不足,能从源头上提高养殖水体的自净能力,从而保护及修护养殖水体水质。 相似文献
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养殖水体富营养化是现今凡纳滨对虾养殖面临的问题,水体富营养化主要是养殖环境中浮游植物过量生长,深层次的原因是对虾养殖中过量的投饵及高密度的养殖模式等导致水体中氮、磷等元素含量增高,产生一些对对虾有害的水质因子.贝类可以以水中的浮游植物作为饵料,多鳞作为底层鱼可以摄食水体的残饵及有机物,在凡纳滨对虾养殖过程中搭配一定密... 相似文献
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水硬度对七彩神仙鱼幼鱼发育的影响 总被引：4，自引：0，他引：4
采用不同硬度的水对七彩神仙鱼幼鱼进行饲养。6周龄幼鱼在硬度为7.94°dH±0.30°dH时饲养84d后,比在硬度为14.71°dH±0.23°dH水中的幼鱼个体大,生长速度快。表明较高硬度的水有利于七彩神仙鱼幼鱼的生长发育。 相似文献
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The variation of virulence of Renibacterium salmoninarum , the causative agent of bacterial kidney disease (BKD) in salmonid fish, was studied by infecting rainbow trout, Oncorhynchus mykiss (Walbaum), with two isolates (strains 325 and 932) from diseased Atlantic salmon, Salmo salar L., and one isolate (strain 4366) from an apparently healthy Atlantic salmon. Coho salmon, Oncorhynchus kisutch (Walbaum), were injected with the strain 932 to estimate difference in fish species resistance. Fish were removed by random sampling for other study purposes, a study design possible with analysis of lifetime distributions incorporating both sampling-, death- and survival-times. At the end of the experiment, the rainbow trout infected with strains 325, 932 and 4366 had a survival probability of 33%, 51% and 72%, respectively. The coho salmon infected with strain 932 had a 26% survival probability. The strain differences were significant according to the log-rank test, and the risk ratio between the strains ranged from 1·8 to 5·4. The strain from the apparently healthy fish was least virulent. The survival of the fish species was different over time. Rainbow trout were more likely to die early in the time course, but high numbers of coho died later, resulting in an overall risk of mortality of 1·4 in favour of rainbow trout. Differences in virulence may reflect changed selective pressure on R. salmoninarum when introduced from feral stocks into the environment of fish farms. 相似文献
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《水生生物资源》2003,16(5):461-465
Anti-proteinase activity was demonstrated in the seminal plasma of cyprinid fish species (bream, chub, ide, dace, asp, goldfish, roach, common carp) using electrophoretic techniques combined with a detection method based on inhibition of bovine trypsin. We found species-specific protease inhibitors in the seminal plasma of cyprinids. At least three bands of protease inhibitors with different migration rates could be identified by native PAGE. Higher variability was characterized for bands with slower migration rates. Visualization of inhibitors after SDS-PAGE under non-reducing conditions allowed estimation of their molecular weights. Apparent molecular weights were within the range of 51–59 and 47–54 kDa for the bands with slower and moderate migration rates, respectively. The molecular weight of fast migration bands for roach and common carp were estimated to 23 and 30 kDa, respectively. Inhibitors of common carp seminal plasma differed in their affinity toward serine proteases. Three inhibitors in common carp seminal plasma could be visualized using cod and bovine trypsin, but only two inhibitors (of high molecular weight) were recognized with chymotrypsin. There were differences in anti-proteinase activity and seminal plasma protein concentration in relation to the origin of common carp seminal plasma (breeding lines) and time of milt collection (spawning vs. post-spawning season). 相似文献
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该研究通过肉眼观察、镜检,进行干露、饥饿、盐度突降、福尔马林等抗性试验,并采用病毒检测等方法,以期建立评估斑节对虾（Penaeus monodon）虾苗活力和质量标准。结果表明,斑节对虾健康虾苗具有趋光性、集群性,体表光洁,肌肉透亮,肠胃食物充盈等特性。测试虾苗干露时间以15min为宜,健康虾苗干露后能立即恢复活力,而病弱虾苗多出现死亡、昏迷现象;虾苗的成活率随饥饿时间的延长而降低,随福尔马林浓度升高和时间延长而降低,随盐度突降幅度增加而降低。健康虾苗能忍受100～200μL·L^-1福尔马林溶液30min,成活率近100％;在盐度20～30下虾苗的成活情况较好,而其在淡水中仅能存活1h。对虾苗进行病毒检测,可以避免养殖中因虾苗携带病毒而可能导致的病毒性疾病的暴发。 相似文献
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鳟鱼发眼卵和旨种运输是养鳟生产的重要环节。发眼卵多在冬季和早春运输,苗种多在晚春和夏季运输。苗种运输大多以鱼篓充氧进行短距离汽车运输,长途运输冷水性鱼苗种的实例很少。本文总结了金鳟和虹鳟苗种长途运输方法,以期与养鳟业界共同交流提高。一、包装材料和方法内包装材料是苗种运输专用塑料袋,规格54×104cm,外包装是泡沫塑料箱,规格63.5×45.5×30．5cm,纸箱规格64×46×32．5cm。塑料袋采取双层式,内装苗种和水共12.5kg,其中苗种0.5-1．3kg,100－2000尾。起运前苗种停食1－2天。运鱼用水水温调至6℃,鱼、水入袋后袋内… 相似文献
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该研究选取具有多态性的6对微卫星引物对构建的2批合浦珠母贝(Pinctada fucata)完全双列杂交家系的遗传多样性进行了分析。6个微卫星标记在9个家系360个个体中共检测到32个等位基因,有效等位基因(Ne)为1.758 7~3.586 5,观测杂合度(Ho)为0.144 4~0.488 9,期望杂合度(He)为0.432 0~0.722 2,Shannon指数(I)为0.691 9~1.507 4。9个家系都有单态位点,平均Ho为0.129 2~0.466 7,平均He为0.155 0~0.439 6,平均I为0.248 5~0.712 2。有19个位点(占35.19%)极显著地偏离Hardy-Weinberg平衡。各家系之间的遗传距离为0.109 0~1.137 2,遗传相似性系数为0.320 7~0.896 8。家系L4B46与L4B48的遗传距离最大,与D3D313的遗传距离最小。UPGMA法聚类分析显示,9个家系分为3支,L4B48单独成一支,B4D426、B4D427与D4B445聚成一支,其余家系聚成一支。该研究结果为合浦珠母贝家系选择育种的亲本选择与交配设计提供了科学依据。 相似文献
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猪的胎盘属于弥散型胎盘,这种胎盘的结构特点和饲养管理的不当,常常导致母猪胎衣不下发生,给生猪的生产繁殖带来极大损失。本文针对母猪胎衣不下发生病因、综合防治进行详细阐述,旨在对预防和治疗胎衣不下能有所帮助。 相似文献
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Peter Howgate 《Journal Of Aquatic Food Product Technology》2013,22(5):516-532
It is well-established in fish technology that freshness should be measured primarily by sensory procedures, though considerable effort has been expended in looking for nonsensory alternatives. A variety of methods for sensory evaluation of freshness has been described and this historical review traces developments of these methods. Much of the source material derives from the research literature such as research journals and reports of research, and the use of sensory methods in commercial quality control has scarcely been documented. There is a brief discussion of possible future developments in sensory evaluation of freshness. 相似文献