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1.
大黄鱼刺激隐核虫病继发细菌感染致死原因的研究 总被引：4，自引：0，他引：4
为明确大黄鱼刺激隐虫病大量死亡的致死原因,从患刺激隐核虫（Cryptocaryon irritans）病的大黄鱼（Pseudosciaena crocea）肝脏中分离细菌,病情程度较轻的鱼未分离到细菌,非常严重的鱼分离到细菌;分离的菌株经纯化后鉴定为创伤弧菌（Vibrio vulnificus）,利用纯化后的菌株作回归感染试验,其感染率为100%,死亡率为80%。研究表明患刺激隐核虫病的大黄鱼体内的细菌为继发性感染,是导致大黄鱼大量死亡的致病菌,其感染途径为水→伤口→体内。 相似文献
2.
刺激隐核虫病是双斑东方鲀养殖生产中的主要致死性寄生虫病,为安全、有效地防治刺激隐核虫病,开展了硫酸铜对双斑东方鲀幼鱼的急性毒性试验及硫酸铜对双斑东方鲀刺激隐核虫病的治疗效果试验。急性毒性试验结果显示,硫酸铜对双斑东方鲀幼鱼24、48、72、96 h半致死质量浓度分别为7.94、7.12、5.32、4.44 mg/L,其安全质量浓度为1.72 mg/L。刺激隐核虫病治疗试验结果表明,1.0、1.5 mg/L的硫酸铜质量浓度对病鱼治疗有效,药浴后刺激隐核虫虫体活力下降,第3 d部分虫体解体或脱落,药浴5 d治愈;0.5 mg/L硫酸铜对病鱼治疗效果不佳,病情继续发展,第8 d病鱼死亡。临床上建议使用硫酸铜质量浓度1.0 mg/L治疗双斑东方鲀刺激隐核虫病。本研究对其他鱼类刺激隐核虫病及其纤毛虫病治疗也具有一定的借鉴意义。 相似文献
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在三种水温条件下(12℃、20℃、28℃)测定江黄颡鱼(Pseudobagrus vachelli)幼鱼(6．5～8．6cm／p，3．953～8．407 g／p)的耗氧状况，据此计算出幼鱼的瞬时耗氧速率(V，mg／g．h)与溶氧量(DO，mg／L)及水温的相关关系。试验表明：江黄颡鱼耐低氧能力较强；其昏迷点、窒息点随水温的升高而有所增大，28℃时两者分别为0．3183、0．2750 mg／L；江黄颡鱼的瞬时耗氧速率随时间的延长、溶氧量的降低而降低，呼吸类型属于顺应型。 相似文献
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为合理使用福尔马林防治大黄鱼刺激隐核虫病,研究福尔马林对体外刺激隐核虫的灭活效果,并评估其对大黄鱼幼鱼的安全质量浓度范围。结果显示,对幼虫分别药浴处理10、30、60、120min,使幼虫全部死亡的福尔马林质量浓度分别为62.5、62.5、31.3、5.6mg/L;对包囊药浴处理1、2、4h,使包囊全部死亡的福尔马林质量浓度分别为150、75、75mg/L;福尔马林对大黄鱼(3.00±0.78)g幼鱼12、24、48、96h的半致死质量浓度分别为394.7、365.3、334.4、322.8mg/L;治疗试验显示,125mg/L福尔马林药浴2h,可有效防治大黄鱼刺激隐核虫病,存活率显著高于75mg/L组和对照组。试验结果表明,每隔3d,125mg/L的福尔马林药浴处理大黄鱼2h,共3次,可安全有效防治大黄鱼刺激隐核虫病。 相似文献
5.
本文采用在淡水和海水中加入不同浓度的福尔马林,进行鮸鱼刺激隐核虫防治的研究。结果发现,福尔马林质量浓度为221．3mg／L的海水中,鮸鱼12h内无死亡,海水福尔马林对鮸鱼12h,24h,48h,72h,96h时的半致死浓度分别为475．6,413．8,248．1,212．7,200．7mg／L,安全浓度为56．08mtg／L;淡水浸泡鮸鱼的半致死时间为126min;淡水处理刺激隐核虫的半致死时间为26min,海水福尔马林中,处理2h和12h的半致死浓度为62．5,23．3mg/L。全池泼洒20～80mg／L福尔马林可防治刺激隐核虫,淡水浸泡30min后泼洒25mg／L福尔马林效果更佳。研究结果表明,海水和淡水福尔马林对刺激隐核虫的致死浓度处于鮸鱼安全范围之内,淡水浸泡30min后泼洒25mg／L福尔马林可有效防治刺激隐核虫。 相似文献
6.
刺激隐核虫病是海水鱼类养殖中的常发病害,特别是在养殖密度大,养殖品种单一,水质环境差,鱼的免疫功能下降的情况下,是非常容易暴发刺激隐核虫病的。该病一旦暴发,就极难控制,常常造成大规模的死亡和损失。所以对刺激隐核虫病的防治必须采取综 相似文献
7.
大口鲇鱼种耗氧率和窒息点的观测 总被引：11，自引：0，他引：11
对平均全长７．６ｃｍ和１１．６ｃｍ的大口鲇鱼种耗氧率和窒息点进行了测定。结果表明：小规模鲇种耗氧量比大规格低，但耗氧率比大规格高。２种规格鱼种的最高耗氧率分别出现在白天１０：００和１２：００左右。鱼种溶氧窒息点分别为０．３３ｍｌｇ／Ｌ和０．３６ｍｇ／Ｌ，与四大家鱼相似或销强，适合养殖和长途运输。 相似文献
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为研究大黄鱼刺激隐核虫病临床防治技术,采用自主研发的复方中草药“HD-2”以及生石灰、甲醛、双氧水和硫酸铜等作为临床中试药物进行防治试验,并通过药物挂袋预防、药物口服预防及治疗、不同浓度药物药浴治疗等3种试验方法对各种药物防治刺激隐核虫的效果进行评价.结果表明:50 mg·L-1氧化钙、10 mg·L-1三氯异氰尿酸片、100 mg·L-1复方中草药“HD-2”、100 mg·L-1双氧水、200 mg·L-1甲醛、2 mg·L-硫酸铜、2mg· L-1高锰酸钾和淡水浴均可以使鱼体表面的刺激隐核虫活力下降,解体死亡,但使用高锰酸钾、硫酸铜、三氯异氰尿酸和甲醛进行药浴时存在治疗不彻底、安全浓度低、容易造成死亡等安全隐患;在网箱边缘悬挂氧化钙固体和三氯异氰尿酸片,也能使网衣上附着的刺激隐核虫包囊数量下降,大黄鱼死亡率下降,摄食量有所提高;对患病大黄鱼以口服复方中草药“HD-2”的方式进行临床治疗试验,能使部分病鱼恢复摄食,死亡率下降15％～ 30％,病鱼体表和鳃丝上的寄生虫数量分别下降45％和60％,显示出较好的治疗效果. 相似文献
11.
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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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
14.
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
15.
Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 
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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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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
18.
Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load 下载免费PDF全文
下载免费PDF全文 Franz Lahnsteiner 《Aquaculture Research》2017,48(7):3901-3909
This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos. 相似文献
19.
T. Citarasu K. Venkatramalingam M. Micheal Babu R. Raja Jeya Sekar M. Petermarian 《Aquaculture International》2003,11(6):581-595
The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could
lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment
in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 103 to 3.76 × 105 cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load
in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 105 cfu/g).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献