池塘养殖中氨氮的危害及其控制方法

在水产养殖过程中,我们经常碰到池塘中氨氮过高的问题,在高密度精养池塘中这个问题更加严重,给养殖造成了一定的危害。下面,我们就池塘中氨氮的形成、氨氮的危害、氨氮的消除途径以及氨氮的控制方法一一加以阐述。一、池塘中氨氮的形成池塘中的氨氮主要来源于三种途径,即水生动     

3种微生物制剂调控工厂化对虾养殖水质的研究

研究了地衣芽孢杆菌(Bacillus licheniformis,BL)、荚膜红假单胞菌(Rhodopseudomonas capsulate,RC)和乳酸杆菌(Lactobacillusspp.,LB)对凡纳滨对虾(Litopenaeus vannamei)工厂化养殖水质的影响。结果表明,施用不同微生物制剂组合,其作用效果各不相同。各组微生物制剂均能降低水体中氨氮,地衣芽孢杆菌 荚膜红假单胞菌(G1)组、地衣芽孢杆菌 荚膜红假单胞菌(G2)和地衣芽孢杆菌 乳酸杆菌(G3)组NH4 的相对降解率为62%、63%和65%;前21d,G2组降低NH4 效果最明显,相对降解率为79%。在降低NO2-方面,G1组的效果较好,相对降解率为46%;但各处理组对于PO34-、COD均无显著效果。相对而言,G1组改善养殖水质的效果最好。实验中微生物制剂的不同施用频率对水质的净化没有明显的差别。各项水质指标均随养殖时间的推移呈现不断上升的趋势。     

对虾健康养殖技术的关键环节

<正>近年来,全国各地都掀起水产品健康养殖高潮,取得较好的效益及成功的经验,现就广东对虾健康养殖技术中几个关键环节作一个综合介绍。一、虾池放苗前的准备工作1.清池消毒清池主要是将池底污泥和有机物加以处理,使之彻底除去或氧化成为有用的肥料。一是冲洗,利     

无公害水产养殖如何规范用药

随着人民生活水平的提高和国家对食品质量安全管理逐渐走上法制化轨道,为适应我国渔业发展新阶段的要求,全面提高水产品质量安全水平,进一步增强水产品国际竞争力,维护消费者合法权益,保护农业生态环境,促进渔业可持续发展,近年来,国家不断加强标准化基地建设,加大无公害食品、有机食品、绿色食品的培育和认证力度,从源头消除水产品不安全隐患,让消费者吃上绿色环保的水产品。在无公害水产品养殖过程中如何用药进行病害防治,成为养殖过程中影响水产品品质的重要环节。     

复合微生物制剂对虾塘养殖水体生态因子的控制效应

应用利生素-复合微生物制剂对养殖虾塘水体中各项水质因子的控制，含活菌数为10个，g的菌剂，用量为1kg-0．5kg／hm，经二个月的试验，结果表明：有益微生物对提高虾塘水质DO，调节水中PH值及分解有机物(COD)污染和有毒物质有明显的功效。对照塘DO升高20％以上，COD上升16％，NH-N升高11．3％，NO-N升高828．6％，DIN升高101．3％PON升高485％，总有机氮(TN)升高70．7％：而试验塘COD下降12．9％-21．3％NH-N下降43．3％-75．6％，NO-N下降74．8％-100％，DIN下降70．8-94．8％，PON和TN分别下降75．2％-70．7％：和32．3％-38．3％，说明用复合微生物制剂是目前水质处理中一种较为理想的方法。     

凡纳滨对虾养殖池塘中青苔的危害与防控

本文针对凡纳滨对虾养殖过程中青苔滋生的条件、环境等因素进行了详细分析,总结出了青苔对养殖造成的严重危害,如消耗水体中大量营养物质、降低水体溶解氧和产生有毒有害物质等,并提出了适当肥水、合理投饲等切实有效的防控方法,为今后淡化、标粗和养殖凡纳滨对虾提供了可参考的技术依据。     

养殖池塘淤泥的危害及清除方法

养殖池塘经过一段时间的养殖生产,由于死亡的生物体、鱼类的粪便、残饵和有机肥料等不断积累,加上泥沙混合,在池底淤积成厚厚的淤泥,很容易造成水质恶化,既破坏了养殖水体的生产能力,又对水产品的质量造成影响。大量研究和实践证明,养殖池塘淤泥增多,底质恶化,导致有毒有害物质增加,也是造成养殖水体污染的重要原因。所以清除养殖池塘过多淤泥是池塘改造不可缺少的一项工作。     

对虾健康养殖综合集成技术

<正>《对虾健康养殖综合集成技术》是水产工作者和养殖从业人员在多年对虾养殖生产与试验、示范实践中,不断总结经验、积累教训的基础上取得的。下面就"放养对虾苗种健康质量检疫检测技术","养殖池塘环境修复技术"、"应用微生态制剂养殖池塘底质、水质环境调控技术"、     

水产良好养殖规范应用的探讨

一、前言水产养殖是一个高度多样化的生产部门,在各种各样的政治、社会、经济和环境条件下运营,包括许多不同的体系、地点、设备、方法、加工流程和产品。随着水产养殖产量的增长,人们也开始担心可能会给环境、地区及消费者食用安全性带来负面影响。水产品安     

Potential of mixed culture of freshwater prawn (Macrobrachium rosenbergii) and self-recruiting small species mola (Amblypharyngodon mola) in rotational rice–fish/prawn culture systems in Bangladesh

The effects of different stocking densities of freshwater prawn (Macrobrachium rosenbergii) on its growth and production in relation to the presence of small self‐recruiting species mola (Amblypharyngodon mola) were investigated in modified rice fields after rice harvest at Mymensingh, Bangladesh. Keeping the stocking density of mola fixed at 20 000 ha^?1 in each treatment, four densities of freshwater prawn (treatments) were maintained: 10 000, 15 000, 20 000 and 25 000 ha^?1 respectively. The rice plots were limed (CaCO₃) and fertilized with urea, triple super phosphate and cowdung regularly. The prawns were fed daily with commercial pellets. Water quality parameters such as temperature, dissolved oxygen, transparency, pH, total alkalinity, inorganic nitrogen (nitrate, nitrite and total ammonia), chlorophyll a and orthophosphate were determined fortnightly. Numerical analysis of plankton communities was performed monthly. All water quality parameters were found to be within the suitable range for freshwater prawn culture, except high temperature, in the peak summer months. There was a homogenous abundance of plankton communities in all treatments throughout the experimental period. Mola started to breed in the second month of the original stocking with partial harvesting after the second month and continued until the final harvest. The total production of mola ranged between 124 and 152 kg ha^?1 during the 4‐month culture period. The average prawn survival ranged from 49% to 57% without any significant difference among treatments. Freshwater prawn production ranged from 294 to 596 kg ha^?1 with significantly higher production in the treatment where 20 000 ha^?1 freshwater prawn were stocked. This treatment also resulted in a higher net profit margin (74%), indicating that stocking at a combination of 20 000 ha^?1 freshwater prawn and 20 000 ha^?1 mola could be the optimum proposition for prawn–mola culture in modified rain‐fed rice fields after rice cultivation.     

河蟹育苗中几个关键环节的技术处理

河蟹(Eriocheir sinensis)育苗与养殖在北方是继中国对虾育苗与养殖之后又一新兴产业.目前河蟹育苗技术日趋成熟,但在某些技术环节上还不够完善,育苗产量有时还不够稳定.笔者结合几年来从事河蟹育苗的实践,就几个关键环节提出如下粗浅看法.     

罗氏沼虾越冬新技术

罗氏沼虾为热带淡水虾,抗寒能力差。１７—１８℃活动减弱,摄食减少,１４℃以下持续几天就会冻死。罗氏沼虾收获季节成虾大量上市,易造成货多价跌,而干塘捕虾售完后易造成货缺价扬现象。因此,罗氏沼虾的越冬对丰富水产品市场,提高渔业经济效益具有十分重要的意义。...     

青虾苗自繁自育技术

青虾生长速度快,养殖成本低,市场需求量大,销售季节长,生产效益好,是水产养殖的优质品种之一。目前池塘养虾,每1／15hm^2产量可达100kg以上,生产效益可观。自繁自育苗种,是搞好养虾生产,获得较好经济效益的基础,现将青虾苗自繁自育技术介绍如下：     

三疣梭子蟹与对虾混养试验

近年来,我区中国对虾养殖出现连年滑坡,给养虾户造成了较大的经济损失。为改变这种状况,我们调整了养殖品种和养殖模式,并于2003年在我区黑沿子镇毕家(que)5村进行了三疣梭子蟹与南美白对虾混养试验,取得了成功,下面将试验过程总结如下：     

Weight and width relationship of freshwater prawn (Macrobrachium rosenbergii)

It has been shown that there is no significant difference (P < 0·05) in the weight = f (width) and orbit length = f (width) relationships of commercially produced male and female Macrobrachium rosenbergii in Hawaii. A regression equation of the form ? = (A 1 X 7 B) 1 ? has been shown to adequately describe the above relationships. In particularWeight = 0·01278 1 (width) 7 2·5189, R 7 2 = 0·978Orbit length = 0·1828 1 (width) 7 0·77685, R 7 2 = 0.996This relationship allows the development of a simple mechanical prawn size sorter.     

青虾的暂养与活体运输技术

青虾 ,又名河虾 ,学名叫日本沼虾 (Macro brachiumnipponense) ,隶属节肢动物门、甲壳纲、长臂虾科、沼虾属 ,是淡水虾中最重要的一类 ,也是我国产量最大的淡水虾。青虾在我国分布很广 ,江苏、上海、浙江、福建、江西、四川、广东、湖北等省市均有分布 ,它广泛生活于淡水湖泊、     

罗氏沼虾反季节高产养殖研究

１９９７年７月我们在海南文昌市抱罗养殖场实施本项目试验。养殖池塘１１口,总面积６０亩,养殖１３６１８３天。平均获亩产２２１８公斤,个体平均重５７７５克,２０克以上个体达８６％,８５厘米以上个体达９４５％,完成合同下达的各项指标。１池塘条件养殖...     

Food safety hazards and the application of the principles of the hazard analysis and critical control point (HACCP) system for their control in aquaculture production

During the past 20 years there has been a dramatic global expansion in fish farming, with both positive and negative consequences. Although commercial aquaculture has contributed positively to the economies of many producing countries, there are considerable negative environmental and social impacts. In intensive and semi-intensive systems, artificial feeds supplemented with antibiotics are used to prevent the spread of disease and to improve feed conversion ratios. Current knowledge of the health and environmental impact of antibiotics used in aquaculture is poor, particularly in tropical regions. Residues may remain in fish used for human consumption and antibiotics released into the environment can lead to the development of antibiotic-resistant bacteria in the food chain. The accumulation of waste feeds in ponds stimulates the growth of bacteria, including human pathogens, which can contaminate products and lead to foodborne disease and the rejection of products in export markets. In extensive systems, where fish are produced mainly for the domestic market, different food safety concerns exist. The consumption of aquatic plants and raw or partially cooked freshwater fish has been associated with foodborne trematode infections. These are a major public health problem in East and South East Asia and occur when products that are contaminated by the infective stages of the parasites are consumed. This paper reviews food safety hazards associated with products from aquaculture and proposes the application of principles of the hazard analysis critical control point (HACCP) system as a general strategy to control the hazards identified.     

Serum constituents of the Malaysian prawn (Macrobrachium rosenbergii) and pink shrimp (Penaeus marginatus)

Baseline serum values of newly captured Malaysian prawns (Macrobrachium rosenbergii) and pink shrimp (Penaeus marginatus) were determined by Sequential Multiple AutoAnalysis. Both of these species have considerable potential for commercial captive culture.Sex differences in serum constituent levels were found within species. Female pink shrimp had higher serum glucose levels than the males. Malaysian prawn males had higher cholesterol levels than females, and the latter had higher levels or activities of urea nitrogen, creatinine and lactic dehydrogenase.Pink shrimp held under laboratory conditions for 10 days had higher levels or activities of serum glucose and alkaline phosphatase and lower levels or activities of serum inorganic phosphorus, total protein, lactic dehydrogenase and glumatic-oxaloacetic transaminase than pink shrimp sampled immediately after capture.