罗非鱼暴发性流行病的防治研究

近年来，全国各重点养鱼区相继发生银鲫、鲮、鲢、鳙、鲤、罗非鱼等淡水鱼暴发性流行病，造成严重损失，已引起各级水产部门和水产研究者的重视。我们自1988年在湛江的池塘、水库发现该病后，即对湛江、茂名两市的部份水库、池塘进行了调查。1989年选择了全国最大的网箱养殖罗非鱼基地——鹤地水库网箱养殖场作为研究点，进行了系统研究，     

罗非鱼暴发性流行病组织病理的研究

本文报告了由链球菌引起的罗非鱼暴发性流行病组织病理学研究.主要组织病理变化:鳃充血,鳃上皮增生、融合,结构崩解;心肌纤维变性,肌间白细胞浸润;肝脏颗粒变性和脂肪变性;肠道粘膜上皮变性、坏死、脱落、固有膜炎性白细胞浸润;肾脏受损严重,白细胞浸润,肾小管上皮细胞坏死、解体,小动脉血管壁玻璃样变性;眼睛脉络膜和眶骨膜组织炎性坏死,晶状体纤维断裂和脱离.     

尼罗罗非鱼暴发性流行病病原的初步研究

从数起病例中分离到Ｇ－链球菌。对其形态、培养特点、生化反应、毒力及药物敏感性等作了研究。初步认定该菌为尼罗罗非鱼暴发病的病原。采用青霉素治疗效果较好     

水库网箱养殖尼罗罗非鱼暴发性流行病的病因初探

病鱼有眼球外突、腹部膨大、平衡失调等症状。该病发病率为40％～50％，发病死亡率达95％。该病病因是配合饲料营养不全，导致鱼体肝肾等器官发生病变，造成鱼体抵抗力下降，从面继发感染了嗜水气单胞菌嗜水亚种，造成养殖的尼罗罗非鱼大批死亡。     

对暴发性对虾流行病的现场观察

对暴发性对虾流行病的现场观察徐启家，宋秀立，宋吉考（山东省海水养殖研究所，青岛２６６００２）（乳山县母珠岛养虾场，２６４５００）位于乳山湾最东端的乳山县母珠岛养虾场，现有３１个养虾池，总面积２８９６亩。１９９３年６月上旬暂养分苗结束，转入养成阶段，对...     

澄碧河水库网箱养殖罗非鱼暴发性流行病的初步诊断与防治

广西百色地区澄碧河水库大面积网箱养鱼，始于1995年，现已发展到2400多箱，这些网箱大多数是放养罗非鱼。1996年3月份以来，该库网箱养殖的罗非自发生暴发性流行病，造成严重损失。从3月17日至4月14日之间，每天少者死几十公斤，多则数百公斤，有些网箱的鱼已全部死光，损失十分惨重。1996年4月12～14日，笔者受广西区水产局和本所领导的委托，对该库网箱养殖的罗非包流行病进行调查和诊断。现将调查情况与防治方法报道如下。l主要症状从外观看，病鱼体色发黑，眼球突出或混浊发白、出血，腹部点状出血，鳃盖内侧出血，腹部膨大、肛门发红…     

暴发性流行病综合疗法

笔者根据两年多的跟踪调查和养鱼者的疗效信息反馈,确认采用四种药物进行综合治疗暴发性流行病,效果十分显著。现介绍如下: 一、综合疗法的原则 先治表后治本,先治水后治鱼,先治虫后治病。即“三先三后”原则,五天为一疗程。 二、材料和方法 1.治疗药物:生石灰,90％晶体敌百虫,威岛牌消毒剂,呋喃唑酮粉剂。 2.病鱼种类:鲢、白鲫、银鲫、鳊鱼、草鱼等。 3.治疗方法 第一天停止喂食,按每亩水面、1米水深用生石灰10—15kg溶水全池泼洒,注意切勿将石灰渣投入池中。块灰有效,粉灰无效。作用:调节pH值,净化水质等。 第二天用0.4—0.7ppm90％晶体敌百虫溶水全池     

长江水产研究所从患病罗非鱼体内发现病毒病原

<正>日前,中国水产科学研究院长江水产研究所鱼类病害研究室曾令兵研究员率领的研究团队,利用电子显微镜、细胞培养、超速离心以及组织病理学等技术,从湖北荆门市某养殖场患病罗非鱼体内首次发现病毒病原。     

鱼类暴发性流行病的防治

近年来,在我国许多淡水养鱼地区暴发了白鲫、鳊、鲢等出血病,其病情来势猛,流行面广,加之并发细菌性烂鳃、赤皮等疾病,死亡率一般在60%左右,有的几乎“全军覆灭”。为此,我们协同有关医学、水产等专家运用祖国医学     

赤点石斑鱼病毒性神经坏死症的组织病理和电镜观察

用逆转录-聚合酶链式反应（RT-PCR）检测患病赤点石斑鱼苗，呈Beta诺达病毒阳性。光学显微镜下观察到病鱼的脑、视网膜、脊髓有空泡．在脑部，空泡主要分布在端脑、间脑和小脑。受感染的细胞明显收缩、致密变化和嗜碱性。包涵体常为圆形，大小不一。透射电镜下，在感染细胞的细胞质可观察到含有病毒粒子的致密体。病毒粒子呈等面体，无外膜，直径为25～28nm，随机分布在细胞质或在致密体内排列成品格状。致密体大小不一。偶尔观察到较大致密体的外膜已破裂，病毒粒子被释放到细胞质。     

First report of viral erythrocytic necrosis in Alaska, USA, associated with epizootic mortality in Pacific herring, Clupea harengus pallasi (Valenciennes)

Abstract. Viral erythrocytic necrosis (VEN) has been associated with large epizootics and high mortality in Pacific herring, Clupea harengus pallasi (Valenciennes), from two different locations in south-eastern Alaska, USA. Clinical signs of disease included whirling, pale gills, watery colourless blood, discoloured livers, pathog-nomonic magenta erythrocytic inclusion bodies and histopathological changes consistent with other infectious haemolytic anaemias in higher animals. Transmission electron microscopy confirmed the presence of iridovirus-type particles associated with the cytoplasmic erythrocytic inclusion bodies. Other apparently healthy herring of various age classes from four additional areas in south-east Alaska also had clinical signs of VEN suggesting a wide distribution of the virus in Alaskan Pacific herring populations. Evidence regarding the two herring epizootics indicated that osmoregulatory stress may have precipitated mortalities in fish having severe anaemia caused by the VEN virus. This is the first reported occurrence of VEN in Alaska and the first natural epizootic known to be associated with the disease.     

池塘养殖患病泥鳅两种病毒病原的电镜观察初报

利用电子显微镜技术,对湖北荆州池塘养殖患病泥鳅的组织进行超薄切片电镜观察。电镜观察结果显示:在患病泥鳅的脾脏、肾脏、心脏及肠道组织中观察到大量球形和杆状两种形态的病毒颗粒。球形病毒颗粒无囊膜,直径约50~75 nm;杆状病毒颗粒有囊膜,形态多样,大小约为(50~100)nm×(300~500)nm;细胞培养分离病毒结果显示,球状病毒可在鲫鱼脑组织细胞系(Gi CB)中增殖,可导致细胞出现典型的细胞病变效应(CPE,cytopathic effect),但没有观察到Gi CB细胞中杆状病毒的增殖。     

Seasonal intestinal coccidiosis in wild bluegill Lepomis macrochirus is associated with a spring bacterial epizootic

Wild bluegill, Lepomis macrochirus Rafinesque, succumb to seasonal mortality in the early spring during cool water temperatures, shown previously to be related to bacteraemia caused by a psychrotrophic bacterium, Pseudomonas mandelii. In the study herein, intestinal coccidiosis in wild bluegill had seasonal prevalence causing heavy intestinal infections and sloughing of intestinal epithelium occurring in late winter/early spring. Infections were predominantly related to two different species, Goussia washuti n. sp., an epicellular coccidium, and a coccidium closely resembling Goussia desseri Molnár 1996, previously only described in percid fish in Europe. In 2019, co‐infections of bacteraemia and intestinal coccidiosis occurred in bluegills. Evaluating coccidium infection intensity by fresh parasite examination and histology, an association was observed in which fish with moderate‐to‐heavy intestinal coccidiosis were 8–12 times more likely to have bacteraemia compared to fish with no or light coccidiosis. The association of these co‐infections suggests that intestinal coccidiosis could contribute to seasonal bacterial epizootics of wild bluegill.     

A mortality event in wrasse species (Labridae) associated with the presence of viral haemorrhagic septicaemia virus

Viral haemorrhagic septicaemia (VHS) is an infectious disease of farmed and wild fish and has an extensive host range in both freshwater and marine environments. In December 2012, a wrasse population consisting of ballan, Labrus bergylta (Ascanius), corkwing, Symphodus melops (L.), cuckoo, Labrus mixtus L., goldsinny, Ctenolabrus rupestris (L.), and rock cook, Centrolabrus exoletus (L.), held at a marine hatchery in the Shetland Isles, Scotland, experienced a mortality event. Approximately 10 000 wrasse were being held at the facility on behalf of an Atlantic salmon, Salmo salar L., aquaculture company prior to being deployed for the biological control of parasites on marine pen Atlantic salmon, aquaculture sites. Fish Health Inspectors from Marine Scotland Science initiated a diagnostic investigation, and subsequent diagnostic testing confirmed the site to be VHSV positive by qRT-PCR and virus isolation followed by ELISA. A VHSV genotype-specific qRT-PCR assay revealed that the isolates belonged to genotype III, the European marine strain of the virus. The virus genotype was further confirmed by nucleic acid sequencing of the partial nucleoprotein (N) and glycoprotein (G) genes followed by BLAST nucleotide searches. This study reports for the first time the detection of VHSV within multiple wrasse species and highlights the need for a comprehensive risk-based approach to the use of wrasse and other finfish species as biological controls within the aquaculture industry.     

Aeromonas sobria, a causative agent of disease in farmed perch, Perca fluviatilis L

Significant numbers of perch, Perca fluviatilis, raised on a pilot fish farm in Switzerland presented focal skin lesions on the lateral sides and fin rot. Mortality rates reached levels of up to 1% of the total fish on the farm per day. Virtually pure cultures of Aeromonas sobria were isolated from the liver, kidney, spleen and skin lesions of affected fish. Aeromonas sobria isolated from the farmed perch had a haemolytic effect on sheep and trout erythrocytes, autoaggregated, was cytotoxic for cultured fish cells and possessed genes involved in type III protein secretion. Experimental infection of naive perch with a single colony isolate of A. sobria from an affected farm fish resulted in the development of clinical signs identical to those seen on the farm. The results indicate that A. sobria can act as a primary pathogen of perch.     

鳢流行性溃疡综合征病原分离鉴定与病理形态学观察

为寻找冬春季鳢(Channa maculata)烂身病的病原,应用组织压片、组织切片、扫描电镜技术、HE 常规染色法和 Grocott 六胺银染色法、霉菌分离纯化及 ITS 的序列分析等对冬春季患疑似溃疡综合征的烂身病鳢进行了病原学与病理学研究。病变组织压片观察到大量直径 10~20 μm,分枝较少、纤细菌丝。扫描电镜观察到肌肉组织中延伸出大量的纤细的丝状真菌。患病鳢皮肤和肌肉表现为变性、坏死与炎性细胞浸润,溃疡灶肌肉内可见大量的慢性肉芽肿结节和炎性细胞浸润。结节基本结构由类上皮细胞和多核巨细胞、炎性细胞、霉菌菌丝(横断面呈圆形,斜断或纵断呈丝状)组成,霉菌位于结节中央。Grocott 六胺银染色观察到结节中有大量棕色菌体。无菌分离培养可观察到典型丝状霉菌;霉菌在灭菌池塘水 20℃过夜, 12 h 后可观察原代孢子群形成,真菌 ITS 序列分析表明其与侵袭丝囊菌(Aphanomyces invadans)同源性为 100%。侵袭丝囊霉菌(A. invadans)是杂交鳢溃疡综合症病的主要病原,为鱼类流行病学调查和疾病防治的深入研究奠定基础。