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1.
近年来包括急性肝胰腺坏死病(AHPND)在内的多种新发疫病的流行,使我国甲壳类养殖业遭受了严重的经济损失。为了筛查导致山东潍坊某养殖场中一虾蟹混养池塘内患病三疣梭子蟹感染的可能病原,本研究采用分子生物学检测方法,对三疣梭子蟹样品进行了白斑综合征病毒(WSSV)、传染性皮下及造血组织坏死病毒(IHHNV)、虾血细胞虹彩病毒(SHIV)、致急性肝胰腺坏死病副溶血孤菌(Vp_(AHPND))、虾肝肠胞虫(EHP)、偷死野田村病毒(CMNV)、黄头病毒(YHV)和肝胰腺细小病毒(HPV)等8种病原的检测,并对样品进行了组织病理和原位杂交分析。分子生物学检测结果显示,患病三疣梭子蟹样品呈Vp_(AHPND)阳性,而呈现WSSV、IHHNV、SHIV、EHP、CMNV、YHV和HPV阴性。对样品进行Vp_(AHPND)套式PCR第二轮扩增产物的序列测定、比对和进化树分析,结果显示,扩增产物序列与致病副溶血弧菌质粒上pirA~(vp)毒力基因片段具有99%的同源性,该序列与已报道的多个致病副溶血弧菌PirA聚在进化树的同一主分支上。组织病理学分析显示,患病三疣梭子蟹的肝胰腺小管上皮细胞坏死,心肌纤维呈溶解样病变,鳃丝上皮柱突细胞明显坏死,胸神经节的神经细胞损伤严重,并且这些组织中还可见大量的细胞核固缩现象;原位杂交结果显示,肝胰腺、心肌、鳃组织及胸神经节中的病变部位均存在Vp_(AHPND)探针的蓝紫色杂交信号。以上表明,虾蟹混养池塘中三疣梭子蟹在自然状态下感染了Vp_(AHPND),并导致肝胰腺、心肌、鳃和胸神经节发生了严重病理损伤。本研究首次在养殖三疣梭子蟹中检测到Vp_(AHPND)感染并揭示了感染所致的病理变化,相关结果为揭示Vp_(AHPND)自然宿主种类和养殖三疣梭子蟹病害防控提供了基础信息。  相似文献   

2.
为了探讨三疣梭子蟹、无齿相手蟹和中华绒螯蟹的鳃与其所处生境的关系,分别采用电镜和生化手段观察比较了3种蟹鳃丝的超微结构,并分析了其总脂和脂肪酸组成及含量。结果表明,3种蟹鳃丝均具有相似的超微结构,而其鳃中线粒体个数和微绒毛结构差异显著。中华绒螯蟹前鳃的线粒体个数显著高于其他两者(P＜0.05),后鳃中三疣梭子蟹的线粒体个数显著低于其它两者(P＜0.05);三疣梭子蟹鳃的微绒毛较其余两者稀疏。3种蟹总脂及脂肪酸含量存在一定差异性,其中三疣梭子蟹中甘油三酯(TG)含量最高,前鳃中TG含量高出其余两种蟹3倍以上(P＜0.05);无齿相手蟹的胆固醇(Cho)含量显著高于其余两者(P＜0.05);磷脂(PL)在3种蟹鳃中的含量均无显著性差异(P＞0.05)。花生四烯酸(ARA)和高不饱和脂肪酸(HUFA)在无齿相手蟹鳃中的含量显著高于其他两者(P＜0.05)。实验结果表明,3种蟹鳃丝超微结构和脂类含量的差异与其生活的环境密切相关,这更利于其生理功能的正常发挥和对环境的适应。  相似文献   

3.
为进一步掌握上海地区养殖凡纳滨对虾(Litopenaeus vannamei)病原的流行趋势及特点,定期对上海主养区的凡纳滨对虾开展了8种流行病病原监测及分析工作。51份样品的分子检测和细菌分离鉴定结果显示,有4种病原检测出阳性,其中虹彩病毒1(DIV1)阳性检出率为29.41%,传染性皮下及造血组织坏死病毒(IHHNV)为3.92%,致急性肝胰腺坏死病副溶血弧菌(VpAHPND)为1.96%,副溶血弧菌(Vp)为19.61%;而白斑综合征病毒(WSSV)、桃拉综合征病毒(TSV)、偷死野田村病毒(CMNV)、虾肝肠胞虫(EHP)等4种病原未检出。408项病原检测结果中,4种病原的阳性总样本数量为28份,总体阳性率为6.86%。结果表明,上海地区养殖凡纳滨对虾的病原携带率处于较低水平,DIV1、副溶血弧菌(Vp)是携带的主要病原。在实际生产中应根据病原流行特点,从苗种选购、养殖过程管理、药物选用等方面进行综合防控,减少病害发生。  相似文献   

4.
应用PCR方法检测患“黄水病”锯缘青蟹中的血卵涡鞭虫   总被引：3，自引：0，他引：3  
"黄水病"是目前锯缘青蟹养殖过程中的主要疾病之一,病蟹主要症状表现为肌肉白浊,体液呈土黄色或浊白色牛奶状。因该病流行范围广、发病率和死亡率高,给青蟹养殖业主造成巨大经济损失,严重地影响了青蟹养殖的健康发展。本研究从病蟹体液中发现大量疑似血卵涡鞭虫的寄生原虫,应用已建立的梭子蟹血卵涡鞭虫病的PCR检测方法对患"黄水病"青蟹进行检测。结果从患病青蟹组织的DNA中扩增出产物大小为585bp的特异性目的片段,经序列分析比较,与三疣梭子蟹上发现的血卵涡鞭虫的序列同源,同源性达99.7%。综合病原流行病学调查、组织病理学、电镜观察等分析结果,初步确定血卵涡鞭虫是引起养殖青蟹"黄水病"的重要病原。  相似文献   

5.
为分析成熟雌、雄三疣梭子蟹、锯缘青蟹和中华绒螯蟹的肌肉、肝胰腺及生殖腺中脂肪酸的组成特点及其差异,以氯仿—甲醇溶液提取总脂,通过10%浓硫酸—甲醇溶液进行甲酯化,采用气相色谱/质谱联用技术分析其脂肪酸组成并进行比较研究。试验结果表明,3种蟹的3种组织中不饱和脂肪酸含量均高于饱和脂肪酸,而在具体组成上又各有特点。3种蟹的卵巢组织中不饱和脂肪酸的含量均显著高于精巢;而在肝胰腺组织中,三疣梭子蟹和中华绒螯蟹雌性个体的不饱和脂肪酸含量显著高于雄性个体;肌肉组织中,锯缘青蟹的雄性个体的不饱和脂肪酸含量显著高于雌性;其余差异不显著。雌、雄中华绒螯蟹中必需脂肪酸含量较高,油酸含量亦较高;雄性三疣梭子蟹肌肉和生殖腺中的花生四烯酸含量较高;而三疣梭子蟹和锯缘青蟹中二十二碳六烯酸和二十碳五烯酸的含量较高,同时多不饱和脂肪酸中ω-3/ω-6的比值亦较高。  相似文献   

6.
利用纯化的三疣梭子蟹(Portunus trituberculatus)"牙膏病"病原微孢子虫对三疣梭子蟹进行人工感染实验,观察感染蟹肌肉组织的临床变化及其超微病理,并测定感染后肌肉和肝胰腺组织酸性磷酸酶(ACP)和超氧化物歧化酶(SOD)不同时间点的活性。结果发现,微孢子虫肌肉注射感染三疣梭子蟹后,蟹的肌纤维透明度随着感染时间的延长逐渐下降并向白浊化转变。超微病理显示,注射感染176 h后,肌细胞内存在大量微孢子虫,感染蟹肌细胞出现核膜肿胀和线粒体双层膜破裂等病变,严重者肌纤维发生断裂、溶解,电镜下可见大量高电子密度的溶解灶。免疫相关酶活分析显示,微孢子虫感染后,三疣梭子蟹肌肉和肝胰腺组织ACP和SOD活性均呈现两个显著上升过程(P0.05);肝胰腺组织ACP活性始终高于肌肉组织,而两种组织的SOD活性恰好相反;感染蟹肌肉组织内两种酶活性几乎始终大于正常对照组。酶活的变化可能与蟹微孢子虫的肌肉组织亲嗜性及其增殖速度较慢等特点有关。  相似文献   

7.
梭子蟹酵母菌人工感染实验和组织病理学初步研究   总被引：2，自引：2，他引：0  
近年,浙江省舟山市暂养梭子蟹(Portunus trituberculatus)连续暴发“乳化病”,发病蟹均分离到一种酵母菌。本实验以该株酵母菌通过肌肉注射方式,对三疣梭子蟹、红星棱子蟹、日本鲟3个品种的健康蟹进行了人工感染实验,以验证其致病性。结果发现,该菌株能感染试验蟹类,并出现与自然发病蟹类似的症状。从感染蟹的体液、肝胰腺、心脏等部位分离到了酵母菌,但未分离到细菌,也未发现寄生虫。酵母菌在病蟹的肝胰腺、鳃、心脏中大量侵袭,并引起这些组织发生以坏死为主的变质性病变,其病理特征主要表现为：细胞肿胀、变性、坏死,某些细胞的细胞核固缩、碎裂或崩解。初步确认该酵母菌是引发梭子蟹“乳化病”的病原。  相似文献   

8.
应用半静态双箱模型室内模拟实验, 研究三疣梭子蟹(Portunus trituberculatus)体内镉(Cd)的蓄积特异性; 并通过分析钙离子(Ca2+)对三疣梭子蟹可食用部位镉(Cd)富集和释放影响, 提出三疣梭子蟹 Cd 污染防控建议。通过双箱动力学模型对三疣梭子蟹体内 Cd 含量变化进行非线性拟合, 得到富集速率常数 k1和排出速率常数 k2, 进而得到生物富集系数(BCF)和生物学半衰期(B1/2)。结果显示, 1 μg/L、5 μg/L 和 50 μg/L Cd 暴露组三疣梭子蟹肝胰腺组织对 Cd 的 BCF 明显高于肌肉组织, 三疣梭子蟹肝胰腺组织中 BCF 和 k1 均随水体中 Cd 浓度的增加而增加, 1 μg/L, 5 μg/L 和 50 μg/L Cd 暴露组对 Cd 的 BCF 分别为 12.16、112.77 和 260.11; 肌肉组织中吸收速率常数 k1 与释放速率常数 k2 均随水体中 Cd 浓度的增加而增加, 由低到高 Cd 暴露组对 Cd 的 BCF 分别为 1.85、2.45 和 1.97。各浓度暴露组肝胰腺中 Cd 暴露风险指数(THQ)除 1 μg/L 组外, 均大于 1, 存在严重健康暴露风险; 各浓度暴露组肌肉中的 THQ 均小于 1, 没有明显的健康暴露风险。另外, Ca2+对三疣梭子蟹肝胰腺和肌肉中 Cd 富集和释放影响的实验结果表明, Ca2+的加入能够有效降低三疣梭子蟹肝胰腺和肌肉对 Cd 的富集, 并促进肝胰腺对 Cd 的释放。本研究结果为三疣梭子蟹 Cd 污染防控和食用方案的提出提供了理论基础。  相似文献   

9.
2009年10月江苏赣榆地区某养殖场养殖的三疣梭子蟹出现大量死亡,症状主要表现为:病蟹行动缓慢、不摄食,蟹体消瘦,打开头胸甲可见肝胰腺、鳃、肌肉等内脏组织水肿,部分肝胰腺和肌肉组织呈腐烂状。从患病梭子蟹肌肉、肝胰脏、体内积液中分离到大量优势生长的细菌。人工感染试验,证明分离菌(JG091120-1)对健康三疣梭子蟹具有很强的致病性。对分离菌进行了形态特征、理化特性等常规表型生物学检验,同时利用分子生物学方法测定了代表菌株的16S rRNA和gyrB基因序列,其中分离菌16S rRNA基因序列长度为1 451 bp(登录号HQ170626),gyrB基因序列长度为1 186 bp(登录号HQ170627),分析了16S rRNA和gyrB两种基因序列的同源性。根据分离菌的表型及分子生物学特性,判定该菌为肠杆菌科枸橼酸属的弗氏柠檬酸杆菌。定居因子抗原cfa是肠杆菌科产肠毒素细菌的一种重要致病因子,利用特异性引物进行cfa基因的PCR扩增,分离菌可以扩增出大小在100 bp的基因片段,表明本次分离的病原弗氏柠檬酸杆菌具有cfa毒力因子。  相似文献   

10.
上海郊区养殖的罗氏沼虾出现了头部“白点病”,造成大量沼虾死亡。患病罗氏沼虾的明显临床症状是位于额角基部的造血组织呈白色不透明状。组织病理学检查表明,病虾造血组织细胞出现异常的嗜碱性包涵体。超微病理研究发现,其造血细胞的细胞质被大量病毒颗粒侵染,该病毒颗粒呈二十面体结构,直径大小为(153±8)nm。聚合酶链式反应(PCR)检测表明,该病毒三磷酸腺苷(ATP)酶基因与十足目虹彩病毒(DIV1)基因序列一致性达100%。根据综合病理和分子检测结果,确认此次上海地区养殖罗氏沼虾“白点病”是由十足目虹彩病毒(DIV1)导致的。文章可为罗氏沼虾“白点病”的诊断和病害防控提供理论依据。  相似文献   

11.
In August 2008, a massive epizootic occurred among Portunus trituberculatus reared together with Palaemon carincauda Holthuis and Sinonovacula constricta in the seawater pond of Ningang farm, Rudong district, Jiangsu province, China. The disease occurred in crabs from juveniles to adults, and the mortality rate reached 30–40%. The diseased crabs exhibited lethargy, hepatopancreas turgidity, and elevated levels of turbid hemolymph. A gram-negative, rod-shaped bacterium (designated as strain LGS-1) was isolated from the ascitic fluid of the diseased and moribund crabs and was confirmed as the causative agent by our infectivity study. We conducted morphological and biochemical characterization of LGS-1, and sequenced the 16S rRNA gene, which led us to identify the bacterium as Vibrio metschnikovii. Drug sensitivity tests showed that this pathogenic bacterium is sensitive to florfenicol, orfloxacin, and SXT, but completely resistant to antibacterial drugs like gentamicin, erythrocin, and acheomycin. This is the first report on Vibrio metschnikovii as a virulent pathogen for Portunus trituberculatus.  相似文献   

12.
A 120‐day trial was conducted to assess the effects of dietary fish oil replacement with vegetable oils on growth, lipid metabolism and antioxidant capacity of subadult swimming crab Portunus trituberculatus. Five isonitrogenous and isolipidic diets were formulated to replace 0, 250, 500, 750 and 1000g/kg of fish oil with a mixture of soybean and rapeseed oil (defined as D1–D5), and each treatment had 30 replicate crabs. Dietary fish oil replacement had no significant effects on growth of the crabs, while the D3 had the highest hepatosomatic index and total lipids in hepatopancreas. The triglyceride and lipase activities in hepatopancreas increased significantly with increasing dietary fish oil replacement. The D4 had the highest levels of alkaline phosphatase (ALP) and acid phosphatase (ACP) in the hepatopancreas, as well as the haemolymph ALP, ACP and peroxidase. The highest levels of haemolymph total antioxidant capacity, catalase and malondialdehyde were detected in D1. Total n‐3 polyunsaturated fatty acids levels in hepatopancreas decreased significantly with increasing dietary fish oil replacement. In conclusion, dietary fish oil replacement had no significant effects on growth of P. trituberculatus, and 500g/kg of fish oil replacement could improve antioxidant capacity, but excessive replacement level will enhance lipid accumulation and peroxidation in the hepatopancreas.  相似文献   

13.
盐度胁迫对三疣梭子蟹鳃Na+/K+-ATPase酶活的影响   总被引：2，自引：2，他引：0  
江山  许强华 《水产学报》2011,35(10):1475-1480
通过钼蓝法测定三疣梭子蟹在3组实验盐度的胁迫过程中第2对和第6对鳃Na+/K+-ATPase酶活的变化,比较了3组实验盐度胁迫1 d时,鳃Na+/K+-ATPase的酶活大小。结果表明,在盐度胁迫初期,3组实验盐度下第2对和第6对鳃Na+/K+-ATPase的酶活下降;之后,各组实验盐度下第2对和第6对鳃Na+/K+-ATPase的酶活开始随胁迫时间增长而上升;最后,各组实验盐度下第2和第6对鳃Na+/K+-ATPase的酶活下降并趋于稳定。另外,胁迫1 d时,各组实验盐度下三疣梭子蟹前5对鳃Na+/K+-ATPase的酶活显著低于后3对鳃Na+/K+-ATPase的酶活。三疣梭子蟹对盐度变化的调节可分为被动应激期(酶活力下降)、主动调节期(酶活力逐渐上升)和适应期(酶活力稳定);三疣梭子蟹后3对鳃是离子转运、渗透压调节的主要部位。  相似文献   

14.
A female swimming crab (Portunus trituberculatus) with fully developed ovaries is considered one of the most nutritious types of seafood. The fishing yield of P. trituberculatus in China has always been high; however, its economic value has been low and unreliable due to poor ovarian development and low nutritional value. Artificial fattening is an effective way to improve the value of wild‐caught crabs, and this study focused on analysing the ovarian development and nutritional quality of the female P. trituberculatus during an artificial fattening period. Therefore, this study provides scientific evidence on the effects of artificial fattening on female P. trituberculatus and can guide the development of nutritional quality regulations for wild‐caught female crabs during the fattening process. The results showed that the ovaries of the wild female P. trituberculatus developed gradually. The ovarian morphology became bulkier, while the gonadosomatic index (GSI) and total edible yield (TEY) were significantly improved after artificial fattening. Significant changes in the nutritional components of the edible tissues were observed, and the moisture content in the ovaries and hepatopancreas decreased continually, while both the protein and fat content in the ovaries significantly increased. Moreover, the fat content in the hepatopancreas significantly increased. The saturated fatty acids(ΣSFA) in the ovaries and hepatopancreas had an increasing trend after fattening, while ΣPUFA and Σn‐3PUFA first decreased and then increased. In contrast, the ratio of Σn‐3PUFA to Σn‐6PUFA decreased steadily. However, the fatty acid composition of the muscles did not change significantly. The levels of all the amino acids increased continuously during the fattening process, and EAA increased significantly in the early stages of the fattening period. Consequently, all amino acids became nonlimiting amino acids after fattening. Furthermore, the ratio of EAA/NEAA in the ovaries increased continually until the end of the fattening period. On the other hand, the fatness and TEY increased significantly after artificial fattening. In addition, the nutritional value significantly improved with the exception of the high‐quality fatty acids in the ovaries and hepatopancreas, which were slightly lower in both.  相似文献   

15.
Mud crab, Scylla serrata (Forskal), is the most commercially important marine crab species in China. In recent years, serious diseases have occurred in major mud crab culture regions in SE China. PCR detection of white spot syndrome virus (WSSV) in diseased mud crabs collected from Zhejiang Province during 2006–2008 showed a prevalence of 34.82%. To study the pathogenicity of WSSV to mud crab, healthy mud crabs were injected intramuscularly with serial 10‐fold dilutions of a WSSV inoculum. The cumulative mortalities in groups challenged with 10?1, 10?2, 10?3 and 10?4 dilutions were 100%, 100%, 66.7% and 38.9% at 10 days post‐injection, respectively. All moribund and dead mud crabs except the control group were positive for WSSV by PCR. Based on the viral load of the WSSV inoculum by quantitative real‐time PCR, the median lethal dose (LD50) of WSSV in S. serrata was calculated as 1.10 × 106 virus copies/crab, or 7.34 × 103 virus copies g?1 crab weight. The phenoloxidase, peroxidase and superoxide dismutase activities in haemolymph of WSSV‐infected moribund crabs, were significantly lower than the control group, whereas alkaline phosphatase, glutamate‐pyruvate transaminase and glutamic‐oxaloacetic transaminase were higher than in the control group. WSSV was mainly distributed in gills, subcuticular epithelia, heart, intestine and stomach as shown by immunohistochemical analysis with Mabs against WSSV. The epithelial cells of infected gill showed hypertrophied nuclei with basophilic inclusions. Numerous bacilliform virus particles were observed in nuclei of infected gill cells by transmission electron microscopy. It is concluded that WSSV is a major pathogen of mud crab with high pathogenicity.  相似文献   

16.
中华绒螯蟹肝胰腺白化症的病因研究   总被引：5，自引：0，他引：5       下载免费PDF全文
2002年10月以来,通过逐户访问及调查问卷的形式对2001～2002年东太湖中华绒螯蟹(Eriocheir sinensis)养殖区"白膏症"发病症状、扣蟹的来源、投饵模式、水草覆盖率、螺蛳投入量、底泥状况、回捕率、产量等进行较为系统的调查。同时对病蟹进行寄生虫检查、病原微生物分离、回接攻毒及病变组织的电镜观察等病原学研究,结果未发现致病性生物。调查结果表明,中华绒螯蟹"白膏症"的发病率雄蟹显著高于雌蟹,其症状为甲壳发黄,头胸甲腹面下肝区发白色或青黑色,肝胰腺由正常的橘黄色变成淡黄或白色;症状严重的病蟹胸腔积水,肌肉松驰萎缩,肝胰腺呈糜烂状,鳃丝发黑。调查结果显示,"白膏症"的发生与饵料的投喂量、动植物饵料之比及水环境有着密切的联系。根据该病的主要症状及发病原因,认为该病应命名为中华绒螯蟹肝胰腺白化症。  相似文献   

17.
不断壮大的东海近海笼壶渔业对三疣梭子蟹（Portunus trituberculatus）等甲壳类资源造成了巨大的压力,实施养护幼蟹的管理措施已成为渔业管理者和生产者的共同呼声。本研究通过海上对比试验,分析了放大网目尺寸对蟹笼渔获效率的影响,运用SELECT模型估算了蟹笼对三疣梭子蟹的尺寸选择性,结合混合影响模型探讨了作业时间和可捕群体对选择性分析的影响。结果显示,对照蟹笼（网目尺寸32.0 mm）与试验蟹笼（网目尺寸分别为52.3 mm和59.7 mm）的三疣梭子蟹渔获甲宽分布存在显著性差异;SELECT模型拟合结果显示试验蟹笼与对照蟹笼的相对作业强度无显著性差异,网目尺寸分别为52.3 mm和59.7 mm的试验蟹笼对三疣梭子蟹的50%选择甲宽（CW50）分别为86.9 mm和90.9 mm,选择范围分别为15.9 mm和9.2 mm。试验蟹笼的CW50远未达到浙江省等当前的最小可捕尺寸规定,表明蟹笼渔业中仅依靠放大网目尺寸可能难以实现幼蟹的有效释放。结果分析显示,在此次试验中作业时间和可捕群体的数量对蟹笼的选择性没有显著性影响。  相似文献   

18.
An 8‐week feeding trial was conducted to evaluate the effects of dietary lipid sources on growth performance, antioxidant enzyme activities and biochemical composition of juvenile swimming crab Portunus trituberculatus of initial weight 2.34 ± 0.08 g. Four different diets were formulated to contain fish oil (FO), soybean oil (SO), linseed oil (LO) or palm oil (PO). The highest final body weight, weight gain, specific growth rate and molting frequency were observed in crabs fed the FO diet. Crabs fed the SO diet showed higher glutathione peroxidase, superoxide dismutase (SOD) and catalase (CAT) activities in both serum and hepatopancreas than those fed the FO diet. The lowest malondialdehyde concentration in hepatopancreas and serum were occurred at crabs fed the SO diet. Crabs fed the LO diet had significantly higher SOD and CAT activities in hepatopancreas compared with those fed the FO diet. Crabs fed the PO diet had the highest activities of fatty acid synthase and carnitine palmitoyltransferase 1 activities in hepatopancreas among all treatments. Fatty acid compositions both in hepatopancreas and muscle reflected those of diets. Overall, these findings demonstrated that physiological–biochemical characteristics and lipid metabolism were significantly regulated by different dietary lipid sources. Moreover, dietary SO and LO supplementation could improve antioxidant ability.  相似文献   

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