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梭子蟹假丝酵母菌病初步研究 总被引：3，自引：0，他引：3
2002-2003年,舟山市暂养梭子蟹连续发生被称为“乳化病”的暴发性疾病,并导致大量死亡。发病主要集中在每年10月至翌年2月低水温期的海捕暂养梭子蟹,病蟹蟹体消瘦,肌肉萎缩,横切步足,在断口处有乳白色的液体流出,打开蟹盖,盖内可见大量乳白色液体。从乳白色液体内能镜检出大量酵母菌样微生物,菌体大小为(2.3~7.8)μm×(1.3~6.5)μm,多数呈卵圆形,细胞大多单个或成对排列,多边芽殖。同时,显微组织病理观察可见病蟹肌肉、心脏、肝胰脏以及鳃等部位也可发现相同菌体。该菌可生长在TCBS上形成白色菌落,在孟加拉红上形成红色菌落,经菌体形态、培养特性及生理生化反应,鉴定为假丝酵母菌属酵母菌(Candidaoleophila)。人工感染试验发现,其对健康梭子蟹具有致病性,出现与自然病蟹相同的症状,并在人工感染病蟹中分离出相同菌株,表明假丝酵母菌属酵母菌是该病的病原。 相似文献
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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
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微孢子虫感染三疣梭子蟹的肌组织病理及其免疫相关酶活性 总被引：1，自引：0，他引：1
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
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2014年7月,津冀沿海地区池塘养殖三疣梭子蟹(Portunus trituberculatus)暴发疾病,导致大量死亡。患病梭子蟹有两种不同表现症状:一种症状为停止摄食,空胃、空肠,行动迟缓;肌肉白浊、不透明,最后乳化呈牙膏状;该病死亡率达60%~70%,称之为"肌肉白浊病"。另一种症状为壳软,停止摄食,行动迟缓;肌肉变白浊、水样变化、萎缩;体腔液及组织坏死液化后从组织中大量渗出,不凝固;死亡率可达90%以上,称之为"牛奶病"。通过疾病流行特征、组织病理、病原超微结构等分析,初步判断肌肉白浊病由一种微孢子虫感染而致,虫体大小(1544±250)nm,呈椭球形,极丝圈数8~9圈,具孢壁[厚(130±22)nm],纤毛(长120~500 nm)、极体[(726±200)nm]、极管、固定盘、质膜、核等结构;牛奶病则是由一种血卵涡鞭虫(Hematodinium sp.)感染而致,虫体大小8~10μm,卵圆形,体表多皱褶、凸起,由细胞壁、多核、纤毛等组成。两种患病蟹的肌肉组织病变明显不同:患肌肉白浊病的蟹肌纤维断裂、溃散、浆质化,肌束减少并被团状集聚的寄生虫充斥、占据。电镜观察显示肌纤维细胞破碎、融合,出现大量空泡结构;肌纤维细胞的线粒体、内质网等细胞器解体、消失。患牛奶病的蟹肌束间隙变大,大量血卵涡鞭虫或充斥在间隙中或附着在肌纤维上,导致肌纤维断裂、离散解体,甚至溶解性坏死,组织呈水样变化。电镜观察也证实这两种寄生虫可同时感染三疣梭子蟹个体的同一组织;当肌纤维细胞破碎融合后,两种寄生虫均能寄生在融合后的胞浆中。从发病史来看,肌肉白浊病和牛奶病的发生有蔓延趋势,死亡率趋向更高,已逐步成为三疣梭子蟹养殖的重要疾病。 相似文献
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三疣梭子蟹（Portunus trituberculatus）隶属于甲壳纲（Crustacea）、十足目（Decapoda）、梭子蟹科（Portunidao）、梭子蟹属（Portunus）。又称江蟹、门蟹、枪蟹。是我国海产大型经济蟹类，经济价值高。近几年，浙江舟山各养殖场均出现梭子蟹“牛奶病”，造成巨大的经济损失。梭子蟹“牛奶病”的主要症状是血淋巴液变为乳白色，折断步足可流出大量白色粘液，患病严重时肌肉可全部化为粘液，如牛奶一般，因此被命名。许文军等报道系酵母菌感染引起； 相似文献
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梭子蟹自人工育苗至养成商品蟹出池的各个时期均有病害发生,严重时死亡率高达80%以上。其中危害较严重的为细菌性疾病和寄生虫病。 1 弧菌病 1.1 病原及症状病原体为鳗弧菌、副溶血弧菌及溶藻弧菌。在蚤状幼体各个时期均有发生,尤其在各期变态时更为严重, 发病严重时在4～6小时死亡率高达80%以上。具体症状表现为对饵料的捕捉能力下降,甚至消失,趋光性减弱, 幼体活动不正常,严重时胸部及附肢发红。肉眼能观察到其体色浑浊,肠道发黑；镜检,肠道发黑无食物,眼球部溶出组织液,高倍镜压片检查可看到有弧状黑点即弧菌。成蟹养殖过程中,病蟹瘦弱,呈昏睡状,甲壳上往往有感染创伤,解剖蟹血液不凝固或凝固很慢,高倍镜观察血液可见活动的弧状黑点即弧菌。 相似文献
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三疣梭子蟹是大型食用蟹类，其生长速度快，人工养殖当年可长成商品蟹，是人工增养殖的一个优良品种。但是在我区目前用于养殖的梭子蟹苗种基本上来自于自然海区。为了提高梭子蟹人工育苗技术水平，促进我区梭子蟹养殖产业化的发展，笔者于１９９９～２０００年进行了梭子蟹生产性人工育苗试验，获得了成功并初步摸索出了符合舟山实际的育苗方法。现将梭子蟹人工育苗技术要点归纳如下，供参考。一、亲蟹暂养作为育苗用的抱卵亲蟹，必须活力强，无外伤，附肢健全，卵块坚实，卵块边缘清晰，卵呈淡黄色或棕黄色。不宜选用卵已成熟或接近成熟的… 相似文献
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Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
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下载免费PDF全文 The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna. 相似文献
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Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
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In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg. 相似文献
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Growth hormone (GH) and reproduction: a review 总被引：5，自引：0，他引：5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations. 相似文献
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Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
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Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
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Sandra García‐Garrido Ismael Hachero‐Cruzado Carlos Rosas Pedro Domingues 《Aquaculture Research》2013,44(11):1741-1751
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting. 相似文献
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The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg–1 fish·h–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g–1·ml–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min–1·g–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min–1·g–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated. 相似文献
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There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future. 相似文献