Lymphocystis disease in imported tropical fish

Lymphocystis disease, affecting snake-skin gouramis (Trichogaster peltoralis) and blue gouramis (T. tricopterus), was diagnosed histologically in 2 shipments of imported tropical fish. Typical virus particles were readily demonstrated by electron microscopy in negatively stained preparations and in sectioned tissues. Attempts at viral isolation in 2 fish cell lines (RTG-2 and FHM) were unsuccessful as were attempts to transmit the infection to pearl gouramis (T. leeri).     

Diseases and pathogens associated with mortality in Ontario beef feedlots.

This study determined the prevalence of diseases and pathogens associated with mortality or severe morbidity in 72 Ontario beef feedlots in calves that died or were euthanized within 60 days after arrival. Routine pathologic and microbiologic investigations, as well as immunohistochemical staining for detection of bovine viral diarrhea virus (BVDV) antigen, were performed on 99 calves that died or were euthanized within 60 days after arrival. Major disease conditions identified included fibrinosuppurative bronchopneumonia (49%), caseonecrotic bronchopneumonia or arthritis (or both) caused by Mycoplasma bovis (36%), viral respiratory disease (19%), BVDV-related diseases (21%), Histophilus somni myocarditis (8%), ruminal bloat (2%), and miscellaneous diseases (8%). Viral infections identified were BVDV (35%), bovine respiratory syncytial virus (9%), bovine herpesvirus-1 (6%), parainfluenza-3 virus (3%), and bovine coronavirus (2%). Bacteria isolated from the lungs included M. bovis (82%), Mycoplasma arginini (72%), Ureaplasma diversum (25%), Mannheimia haemolytica (27%), Pasteurella multocida (19%), H. somni (14%), and Arcanobacterium pyogenes (19%). Pneumonia was the most frequent cause of mortality of beef calves during the first 2 months after arrival in feedlots, representing 69% of total deaths. The prevalence of caseonecrotic bronchopneumonia caused by M. bovis was similar to that of fibrinosuppurative bronchopneumonia, and together, these diseases were the most common causes of pneumonia and death. M. bovis pneumonia and polyarthritis has emerged as an important cause of mortality in Ontario beef feedlots.     

Bacterial diseases of marine fish

The principal bacterial diseases found among wild and cultured marine fish are reviewed. The bacterial agents discussed include the Gram-negative pathogens in the Vibrio, Aeromonas, Pasteurella and Edwardsiella genera, Renibacterium salmoninarum and the myxobacteria, streptococci, mycobacteria, nocardias and anaerobic organisms which have been associated with fish diseases. Methods for the isolation and identification of these organisms are described.     

引进的香蕉种质资源对云南枯萎病菌株的抗性评价

枯萎病严重影响香蕉产业的可持续发展。评估香蕉种质资源对云南枯萎病菌株TR4的抗性,遴选和储备抗病种质资源,为香蕉种质资源多样性在云南地区的利用、抗病种质资源和抗病基因的应用提供依据。本研究以国际生物多样性中心引进的11份香蕉种质资源为材料,在温室内接种不同浓度的云南枯萎病菌野生型菌株TR4（15-1）,球茎解剖调查和病情指数分析,将香蕉种质资源分为免疫,高抗,抗病,中抗,感病和高感六个等级。结合已报道香蕉种质资源对其他TR4菌株的抗病性评估,遴选对云南菌株TR4（15-1）抗性较好的香蕉种质资源。在接种常规浓度（1×106孢子数/mL）TR4（15-1）条件下,Kazirakwe,Igitsiri,Mbwazirume,Inkira,Akpakpak,Pahang是云南菌株TR4（15-1）的抗病种质资源,接种20天的病情指数范围是20.31-29.27;GCTCV-119和Gros Michel为中抗种质资源;Baxi Jiao,Banksii和Ibwi是感病种质资源。在高浓度（1×108孢子数/mL）TR4（15-1）侵染下,常规浓度筛选到的6份抗病种质资源仍然表现为抗病,但GCTCV-119,Gros Michel,Baxi Jiao,Banksii和Ibwi均划分为感病种质资源。结合不同浓度病原菌侵染的病害调查分析,11份香蕉种质资源对云南菌株TR4（15-1）的抗性存在明显的差异,抗TR4（15-1）的强度依次为：Kazirakwe> Inkira>Pahang> Akpakpak> Igitsiri> Mbwazirume。本研究遴选到6份香蕉种质资源（Kazirakwe,Inkira,Pahang,Akpakpak,Igitsiri,Mbwazirume）对云南菌株TR4（15-1）具有较好的抗病性,为广谱性抗病资源。研究结果为云南产区香蕉抗病资源的储备、抗病种质的利用、保障云南香蕉产业的稳定发展奠定基础。     

全球鱼类和水产品前瞻

1市场和价格鱼类及鱼产品价格总体下行。由于需求减少．只有那些产量供应紧张的品种才幸免于这场价格下跌风暴．包括野生白鱼和黄鳍金枪鱼、养殖三文鱼和罗非鱼．价格仍趋稳定。其他养殖品种．如欧洲鲷和大菱鲆价格创历史新低,原因是产量大幅增长。另一方面．越南鲶鱼价格尽管在2008年初下跌．不过正在恢复中上涨。     

Molecular detection of betanodavirus in wild marine fish populations in Korea.

Viral nervous necrosis (VNN) is a worldwide disease affecting several species of cultured marine fish. In Korea, VNN has been identified in several species of cultured marine fish. In this study, the authors present data of the amplified nested polymerase chain reaction product (420 bp) of 21 nodavirus strains from different species of apparently healthy wild marine fish on the southern coast of Korea. Phylogenetic analysis based on the partial nucleotide sequence (177 bases) of the RNA2 coat protein gene of 21 strains was highly homologous (93-100%) and closely related to that of the known betanodavirus, redspotted grouper nervous necrosis virus. These results indicate that betanodaviruses occur in large populations of wild marine fish in the southern part of the Korean peninsula, suggesting the importance of these subclinically infected fish as an inoculum source of betanodavirus that is horizontally transmitted to susceptible cultured fish species.     

储藏条件对进口鱼粉储藏品质的影响

试验的目的是考查进口智利鱼粉样品在不同温度、水分和湿度储藏条件下储藏特性指标的变化规律。将进口智利鱼粉样品于培养箱中培养观察28 d。每7 d采样1次,对鱼粉的酸价、组胺和过氧化值理化特性指标进行测定。试验结果表明:在不同的温度、水分和湿度条件下,进口鱼粉的酸价随储藏时间的延长而升高;过氧化值呈现在储藏初期先下降,随后上升的趋势;组胺在不同的储藏条件下呈现先上升后下降的趋势。     

广东省8月玉米、豆粕、进口鱼粉价格分析

1玉米横向整理并略有下调 广东7月份玉米市场价格呈稳中下调局势。7月3日深圳码头玉米报价1450元／t，20日深圳码头容重700以上玉米报价1420元／t，容重680玉米报价1405元／t。业内人士认为，市场消费没呈刚性增长，玉米货源充足，甚至连台风“碧利斯”都无法阻挡玉米船的正常抵达，是广东7月份玉米市场价格必然下调的因素。     

海水鱼类的营养需求及饲料的配制

1我国海水鱼类养殖及饲料使用现状 我国海域辽阔,大陆海岸线长达18 000km,浅海、港湾、滩涂面积大,从南到北跨越热带、亚热带和温带3种气候区,很适于发展海水养殖业.20世纪70年代末开始,海水鱼类养殖蓬勃发展,特别是近几年,随着海水鱼类多种养殖模式的推广以及人工繁殖与育苗技术的突破,养殖技术的日臻成熟,极大地推动了海水鱼类养殖产业的发展.据国家农业部渔业局统计,2005年上半年海水养殖产量达519万t.养殖方式主要有池塘养殖、陆基工厂化养殖、滩涂养殖和网箱养殖等.主要的养殖品种有美国红鱼、真鲷、河豚、鲈鱼、石斑鱼、大黄鱼、牙鲆、军曹鱼等20多种.     

鱼油在水产饲料中的应用

鱼油是湿法加工鱼粉过程中的副产品,是将海洋鱼类及其废弃物经蒸馏、压榨和精炼而得到,以脂肪形式存在于鱼肉中或以分散油形式存在于鱼体内的油脂。鱼油的主要成分是甘油三脂,此外还含有少量类脂、磷甘油醚、脂溶性维生素以及蛋白质降解物等,其中磷脂主要由磷脂酰胆碱和磷脂酰乙醇胺组成。与一般动植物油脂相比,鱼油中大部分脂肪酸具有较长的碳链和多元不饱和度,长链脂肪酸通常占总脂肪量的1/4￣1/3,有时高达1/2,其中5￣6个双键的脂肪酸通常占鱼油的15%￣30%,尤其以n-3系列的高度不饱和脂肪酸(H U FA),如二十碳五烯酸(E PA)和二十二碳六…