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1.
典型增氧设备在养殖池塘中组合应用的研究 总被引：1，自引：0，他引：1
叶轮式、水车式、射流式和曝气式增氧机是目前我国池塘养殖使用的主要增氧设备;由于结构形式和工作原理的不同,4种形式的增氧机有不同的特点和功能。为提高养殖池塘增氧设备的增氧效果,通过增氧设备对养殖池塘水体不同深度增氧效果的试验和养殖池塘自然增氧的试验,分析了4种典型的增氧设备的增氧性能和特点,提出了叶轮式增氧机与耕水机、水车式增氧机与耕水机、水车式增氧机与射流式增氧机以及曝气增氧机与耕水机组合配置使用的混合增氧模式,可以优势互补,充分发挥各种形式增氧设备功能。通过组合使用,达到对养殖池塘水体最大限度的增氧效果的目的。 相似文献
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正增氧机是池塘养殖稳产高产的关键,增氧效果的好坏直接关系到池塘养殖的产量和效益。2014年,大宗淡水鱼产业技术体系呼和浩特综合试验站在土默特左旗2814项目区进行了微孔增氧、叶轮式增氧、涌浪式增氧3种增氧设备增氧效果的对比试验。现将试验情况介绍如下。一、材料与方法1.选择4口面积均为10亩、条件基本一致的池塘作为试验池塘。2.1号池塘配备3千瓦叶轮式增氧机一台,2号、3号池塘配备2.2千瓦微孔增氧设备一套(每个池塘14个盘),4号池塘配备2.2千瓦涌浪式增氧机 相似文献
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水产养殖常用的增氧设备主要有叶轮式增氧机、水车式增氧机、流射式增氧机、喷水式增氧机和曝气增式氧机等。叶轮式或水车式增氧机主要是设置在水体上层,单独使用很难满足养殖池塘的立体增氧要求,而且能耗相对较高。曝气增氧又可细分为气石曝气增氧和微孔管曝气增氧两种,其区别在于气体的扩散器, 相似文献
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微孔曝气增氧与叶轮增氧机增氧在南美白对虾池塘养殖的应用比较 总被引：2，自引：0，他引：2
试验比较了无油滑片式微孔曝气增氧机与传统的叶轮式增氧机对南美白对虾(Penaeus vannamei)养殖池塘的溶解氧、对虾生长及经济效益的影响.经过4个月养殖试验,结果发现,上午10:00时测得的池塘溶解氧都高于5.9 mg/L,但使用微孔曝气增氧的试验塘溶解氧在养殖过程中高于叶轮式增氧机增氧的对照塘;微孔曝气增氧的池塘,7月份和8月份养殖的南美白对虾的全长分别为6.68 cm和8.98cm,体质量分别为3.19g和9.21 g,显著高于叶轮式增氧的池塘(P＜0.05),但9月份收获时终末体长、体质量与对照塘相比无显著差异;试验塘的饲料系数(1.05)低于对照塘的饲料系数(1.16);微孔曝气增氧提高了亩产量,销售利润(3454.1元/亩)是叶轮式增氧机增氧(2308.1元/亩)的1.5倍.微孔曝气增氧是南美白对虾池塘养殖较好的增氧方式. 相似文献
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如何增加池塘中的溶氧量,是水产养殖中遇到的难题。目前,池塘常用的增氧设备是叶轮式、水车式增氧机,这些传统增氧机存在着增氧能力有限、底层增氧量低、增氧不均匀、能耗大、噪声大等缺点,特别是水质改善效果不明显。 相似文献
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应用池塘底部增氧技术养殖南美白对虾效果好 总被引：4，自引：0，他引：4
随着南美白对虾养殖密度的不断提高,单独使用传统的叶轮式或水车式增氧机已经不能满足对虾养殖池塘的立体增氧要求。2005年,我们结合白对虾病害防治试验,在一部分养殖池塘推广应用一种新的增氧模式,即在池塘底部铺设增氧管道,配上水车式增氧机养殖南美白对虾,取得成功。 相似文献
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本文介绍的叶喷式多功能增氧机，其结构综合了叶轮式与喷水式增氧机的特点。试验表明，该机的增氧效果与动力效率均明显高于叶轮式、喷水式增氧机。该机既能用于增氧，又能组合成电动浮泵用于鱼池抽水作业，是一种结构新颖的多功能池塘养殖增氧设备。 相似文献
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微孔曝气式增氧机的性能及应用效果 总被引：2，自引：0，他引：2
为研究微孔曝气增氧机的增氧性能和池塘应用效果,按照标准规定的方法进行了增氧性能的试验和不同水深对增氧性能影响的试验,并在池塘中进行应用效果的试验。结果显示:微孔曝气式增氧机具有比叶轮式增氧机等增氧机更强的增氧能力,但不同配置的机型,增氧能力随配套功率和曝气管长度的增加而增强,动力效率则呈明显下降趋势;增加曝气管布置深度可以提高增氧性能,安装深度从2 m增加到4 m,增氧能力增加285%,动力效率增加207%,与其它养殖池塘机械增氧设备相比,池塘水体越深,微孔曝气式增气机的增氧优势越明显。目前,池塘采用微孔曝气式增氧机的配置方式不具优势,需要改进提升。 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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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 
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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
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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
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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