鱼类中毒与泛塘的差别及解救技术

养鱼池塘，往往因管理上的疏忽而发生塘鱼中毒或泛塘事故，严重时都会死鱼。因此，准确区别中毒与泛塘，并及时采取相应的解救措施，减轻损失，是渔业上一项重要的技术工作。一般可从几方面进行区别和解救。１从发生的时间区别塘鱼中毒一般无季节、天气之分，与池塘水质肥瘦、塘鱼放养密度关系不大，多与厂矿排污时有毒污水进入池塘；或是农田施药时在池塘中清洗药器械；以及防治时用药过量或施用方法不当；个别不法分子投毒偷鱼等有关。中毒死鱼，在白天，夜晚都可发生。泛塘则多发生于夏秋高温季节，特别是连续的闷热天气、连续阴雨天和雷…     

中毒与泛塘的区别及解救技术

养鱼池塘,往往因管理上的疏忽很容易发生塘鱼中毒或泛塘事故,严重时会全军覆没。因此,准确区别中毒与泛塘,并及时采取相应的解救措施,减轻损失,是渔业生产上一项重要的技术工作。     

塘鱼药害与渔塘的判别及解救

养鱼池塘,往往因管理上的疏忽而发生药害或泛塘事故,严重时都会死鱼。但因两者引起死鱼的原因不同而弃区别,因此,准确地判别泛塘与药害事故,并及时采取解救措施,减轻损失,是养鱼生产上一项重要的技术工作。我们可以从下述三方面进行判别: 一、从发生的时间判别药害一般无季节、天气之分,与池塘水质肥瘦、池鱼稀密关系不大。而与工厂排污,农田施药等有关。因有毒污水进入池塘,或是在池塘中清洗施药器械,以及防治鱼病时用药过最,或施用方法不当等。发生药害死鱼,在白天,夜晚均可发生。泛塘则多发生于夏秋高温季节,特别是连续的低气压闷热天气、连绵阴雨天气和雷阵雨下得不透的天气,最易发生泛塘事故。     

中毒与泛塘的判别及解救

养鱼池塘,往往因管理上的疏忽而发生塘鱼中毒或泛塘事故,严重时都会死鱼。因此,准确地判别泛塘与塘鱼中毒事故,并及时采取相应的解救措施,减轻损失,是渔业生产上一项重要的技术工作。我们一般可从下述几方面进行判别和解救:     

夏季常见鱼病及其预防方法

一、泛池往年发生过严重死鱼事件的精养池塘,要特别注意发生浮头的现象。当池养鱼出现严重浮头,不及时处理就易引起泛池,而严重泛池可致使养殖鱼全部死亡。特别是在无风、闷热、打雷不下雨或雷阵雨、暴雨过后等天气异常时要注意。投饵过剩、水质恶化、水源不好,养殖鱼鳃部有病,     

泛池的原因分析及对策

常州市新闸镇两个集体场自１９８６年建成起,至今已发生过三次重大的泛池事故,涉及面积３５亩,死鱼达１．５万公斤左右,而且多以大草鱼为主,给两场的生产带来了较大的经济损失。现就历次泛池的主要原因作一分析、总结,并提出相应对策,供大家参考。一、主要原因１．放养前清塘消毒不彻底,为日后泛池埋下了隐患。２．片面追求产量,放养密度过高,造成水中氧气供应不足。３．鱼场选址不合适,附近无充足的水源,且进排水设计不科学,造成换水困难,水质易恶化。４．高温季节因天气突变引起池塘严重缺氧,是造成泛池的重要因素,多发生…     

鱼类氨氮中毒、药害及泛塘的区别

1.发生时间氨氮中毒多发生在连续晴天,并多在午后。池鱼药害多与农田施药、鱼池施肥和工厂排污有关,在作物的生长季节、病虫害流行期间和鱼病流行期间较为严重,死鱼现象不分白天、夜晚都可发生。而泛塘死鱼多发生在夏季高温季节,特别是在连续低气压闷热天气、连绵阴雨天气最容易发生,并多发生在半夜到清晨这段时间里。泛塘与水质肥瘦、池鱼密度有关,水越肥鱼越密,则泛塘程度也越重。     

高产鱼池防“泛池”

高产鱼池鱼类放养密度大,投饵施肥多,水质肥。在夏秋高温季节,鱼类很容易因池水缺氧而严重浮头,稍有疏忽,即可能发生泛池事故,造成大量死亡,给生产带来严重损失。为了防止泛池事故发生,提高池鱼产量,除应加强日常管理工作外,主要     

怎样防止鱼塘泛塘

池塘水中氧气不足，造成全部或大部分塘鱼浮头窒息死亡，这种现象叫泛塘，也叫翻水或反水。泛塘多在夏秋季节发生，各地都有出现，尤其江南各省更多，严重地影响生产。     

甘肃省8月水产养殖病情预测预报

<正>8月份,是全年中水温最高时期,池塘负荷最大,鱼类食欲旺盛、摄食量大,很容易发生鱼类缺氧浮头甚至泛池事故。预计寄生虫病害和细菌性疾病仍为多发疾病。各养殖场应密切关注天气变化,加强日常管理,做好水质调控,预防养殖鱼类发生浮头或泛塘事故,积极做好鱼病预防工作。一、病情预测1.草鱼、鲤鱼、鲢鳙鱼易发生细菌性烂鳃病、赤皮病、肠炎病及车轮虫、锚头鳋等寄生虫病害,鲤鱼、锦鲤还要预防锦鲤疱疹病毒病。重点关注区域为兰州、白银、酒泉、临夏、庆阳等地区养殖场。     

大肠埃希氏菌和肺炎克雷伯氏菌的药敏试验

大肠埃希氏菌和肺炎克雷伯氏菌是动物肠道内的常见细菌,体弱和幼龄动物受气温变化或食物变换等因素的影响时,肠道内的这些条件性病原菌便大量繁殖,引起胃肠道疾病或败血病。采集这2种病原菌EL-1株(大肠埃希氏菌)和EL-2株(肺炎克雷伯氏菌),在培养基上培养生长,再制备各种抗菌药片进行药敏试验。经动物试验肠霉素试验和抗原性研究,证明EL-1株和EL-2株能致死小白鼠,能产生肠毒素,具有较好的抗原性和较强的毒性。本试验通过药敏试验来检测这2种病原菌对不同抗菌药物的敏感性,以选择出有效药物用于预防和治疗这类疾病。试验表明,EL-1株和EL-2株除对氟哌酸、氟嗪酸、氯霉素和复方磺胺抗菌素有较高敏感性外,对其它抗菌药物具有不同程度抗药性。     

Larviculture of the Greasy Grouper Epinephelus tauvina F. and the Brown-Marbled Grouper E. fuscoguttatus F. in Singapore

This paper reports the larviculture of two grouper species, the greasy grouper Epinephelus tauvina and the brown-marbled grouper E. fuscoguttatus , and examines the technical feasibility of breeding the fish. Fertilized eggs for larviculture were obtained by induced spawning through multiple hormonal injections of the female brooders, followed by artificial fertilization for the greasy grouper and by natural spawning in netcages for the brown-marbled grouper.
For both species, larviculture was divided into three operational stages, i.e., stage 1 (day 0–12), stage 2 (from day 12 to day 24 for the greasy grouper and to day 30 for the brown-marbled grouper) and stage 3 (day 24 or 30 to metamorphosis). Larvae were transferred to clean tanks after each stage. Total mortality around day 5–8 was common for the greasy grouper. Several modifications, including the feeding with super-small strain rotifers, intensive feeding of rotifers with Nannochloropsis and the use of an oil-skimmer, have been made to improve the situation. Two other major problems in larviculture were the high mortality observed after day 25 in the greasy grouper and the high cannibalism from day 35 onwards for the greasy grouper and from day 30 onwards for the brown-marbled grouper. The shock syndrome exhibited by both species during the periods made culling of the fish impossible.
Based on the spawning and larval characteristics, brown-marbled grouper is considered a better potential species for large scale fry production than the greasy grouper.     

Marine ornamental aquaculture in the Northeast U.S.: The state of the industry

This study characterized Northeast U.S. businesses breeding and/or selling marine ornamental aquacultured (MOA) livestock, identified cultured species, and assessed sales figures. Identified businesses (n?=?529) in the region consisted partially of retailers (n?=?274), commercial aquaculturists (n?=?42), and public aquaria, research, and educational institutions (n?=?48); the target sectors for inquiry. Of 75 survey respondents, 54% retailed MOA livestock, 19% conducted their own commercial MOA, and 9% conducted MOA as a part of public aquaria, research and/or educational endeavors. Corals generated up to $60,000 in annual sales for retailers and $100,000 for commercial aquaculturists. Commercial aquaculturists generated up to $50,000 in annual sales for MOA fishes and up to $30,000 for MOA non-coral invertebrates. The industry is characterized by market demand, low supply, few commercial aquaculturists, and many public aquaria, research and educational institutions; these attributes offer opportunities for its regional growth and development.     

The effect of hypervitaminosis D3 on the bones of the hen. 1. Light microscopy studies

46 one day old chickens, divided into five groups, were fed an alternately composed vitamin D3 ration during 36 days. In the group depleted of vitamin D3 the typical rickets were found. When treated with a standard ration (2000 I.U. vit. D3/kg food) after 15 days depletion of vitamin D3 the chickens showed control-group parameters within 3 weeks. Using 60,000 I.U. vitamin D3 after a period of 15 days depletion evoked rather an abrupt beginning of healing tendency accompanied by signs of intoxication which were enhanced in those chickens treated with 120,000 I.U. vitamin D3: increase in number of osteoblasts, calcification of osteoblastic mitochondrial membranes and endothelial cell membranes, as well as degeneration of osteoblasts together with a strong reaction of eosinophils. There did not occur necrosis of osteocytes or of bone structure. Erythrocytes, being embedded in ground substance without endothelial surrounding, was a common finding in every group.     

The effect of hypervitaminosis D3 on the bones of the chicken. 2. Electron microscopic studies

In an experiment of 36 days duration 46 one-day-old chicks were divided into 5 groups and fed with different concentrations of vitamin D3. The animals of the group which lacked vitamin D3, showed the typical rachitic lesions. After a 15 days lack of vitamin D3 the chicks of another group were treated with standard food (2000 I.U. vitamin D3/kg food) with the consequence of an approximation of the analyzed parameters to those of the control group within 3 weeks. When fed with 60,000 I.U. of vitamin D3 after a 15 days lack of this vitamin, the animals showed an over-hasty healing process, ending up with signs of intoxication which were even more conspicuous when fed with 120,000 I.U. of vitamin D3. Besides an increasing calcification of osteoblasts and endothelial cell membranes as well as a degeneration of osteoblasts, a clear increase of eosinophilic granulocytes could be noticed. In all groups free erythrocytes within the ground substance were found. There was no evidence of necroses of osteocytes or of bone.     

Eimeria branchiphila sp.nov. sporulating in the gill filaments of roach, Rutilus rutilus L.

Abstract. Eimeria branchiphila sp. nov. is described from the roach, Rutilus rutilus L., collected in Bulgaria. Sporulated oocysts were found in gill secondary lamellae and less frequently were associated with melano-macrophage centres in the spleen and in kidney interstitial tissue. In the gills, parasite cells identified as zygotes and sporulation stages were also encountered. This unusual site of sporulation represents a mechanism of sporocyst dispersal previously not recorded in fish coccidia.