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牛蛙红腿病烂皮病以及并发病的治疗方法牛蛙的疾病很多，但对牛蛙构成主要危害的是红腿病、烂皮病以及两病同时发生的并发病。一、红腿病是幼蛙和成蛙的常见病。常在养殖密度大、水质条件差的池中发生，得病的蛙精神不振，低头伏地，不活动，不吃食，腿内侧、内股和腹下皮... 相似文献
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牛蛙红腿病的防治方法 总被引：1，自引：0，他引：1
牛蛙红腿病是厦门地区水泥池牛蛙养殖过程中常发生的一种疾病。因其具有暴发快、传染率高、死亡率高(高达80%～90%)等特点,给厦门地区广大养殖户造成极大的损失。作者通过在牛蛙养殖场的现场实践管理及病历分析,总结出一套牛蛙水泥池养殖模式下红腿病的预防与治疗方法,现介绍如下。1发病原因红腿病一般认为是由嗜水气假性单胞杆菌引发的,属于细菌性疾病。此症在牛蛙各养殖阶段皆有发生,常发生于(1)蝌蚪体质较弱的变态时期;(2)温差较大,pH值易转变的季节交替期(夏入秋)及雨季。由于牛蛙红腿病具有很强的传染性,因此被病蛙污染过的水源、排泄… 相似文献
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牛蛙红腿病、烂皮病及并发症的防治 总被引：2，自引：0，他引：2
牛蛙的疾病很多，但对牛蛙构成主要危害的是红腿病、烂皮病以及两病同时发生的并发病。１红腿病１１红腿病是幼蛙和成蛙的常见病。常在养殖密度大、水质条件差的池中发生，得病的蛙精神不振，低头伏地，不活动，不吃食，腿内侧、内股和腹下皮肤有红点、红斑。此病危害大... 相似文献
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牛蛙暴发性细菌性疾病的综合防治牛蛙暴发性细昏性疾病是继牛蛙活饵料后又一个困扰牛蛙养殖生产的严重问题。该病每年５—１０月都可发生，主要在牛蛙幼蛙和成蛙阶段。与常见的牛蛙红腿病、烂皮病、胃肠炎病等不同。主要症状是病蛙常群集于蛙池四周及池角，低头伏地，静卧... 相似文献
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针对引起牛蛙产生红腿病的2种致病菌(嗜水气单胞菌和乙酸钙不动杆菌)制备灭活菌苗,同时对菌苗的安全性、免疫效果、菌苗保存期、牛蛙免疫应答的产生期和免疫期进行了探讨. 相似文献
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牛蛙红腿病菌苗免疫试验 总被引：1，自引：0，他引：1
针对引起牛蛙产生红腿病的2种致病菌(嗜水气单胞菌和乙酸钙不动杆菌)制备灭活菌苗，同时对菌苗的安全性、免疫效果、菌苗保存期、牛蛙免疫应答的产生期和免疫期进行了探讨。 相似文献
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Trichomonads of the oral cavity were found in 9 of 60 investigated horses. Apart from dental tartar, the oral cavity showed no clinical signs in all positive horses. The clinical investigation of these horses additionally revealed colic in 4 and coughing in 4 horses as well as lumbago in 1 animal. By means of scanning electron microscopy the trichomonads were shown to be round or piriform with an average length of 7.6 microns and greatest width of 6.3 microns. They had 4 anterior flagella with an average length of 8.3 microns, an undulating membrane measuring 8.7 microns with no trailing flagellum as well as an axostyle extending on average 7.8 microns beyond the body, and therefore have to be placed into the genus Trichomonas. 相似文献
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Potential and limitations of ozone for the removal of ammonia, nitrite, and yellow substances in marine recirculating aquaculture systems 总被引：1，自引：0，他引：1
J.P. Schroeder P.L. Croot B. Von DewitzU. Waller R. Hanel 《Aquacultural Engineering》2011,45(1):35-41
The high levels of water-reuse in intensive recirculating aquaculture systems (RAS) require an effective water treatment in order to maintain good water quality. In order to reveal the potential and limitations of ozonation for water quality improvement in marine RAS, we tested ozone's ability to remove nitrite, ammonia, yellow substances and total bacterial biomass in seawater, considering aspects such as efficiency, pH-dependency as well as the formation of toxic ozone-produced oxidants (OPO). Our results demonstrate that ozone can be efficiently utilized to simultaneously remove nitrite and yellow substances from process water in RAS without risking the formation of toxic OPO concentrations. Contemporaneously, an effective reduction of bacterial biomass was achieved by ozonation in combination with foam fractionation. In contrast, ammonia is not oxidized by ozone so long as nitrite and yellow substances are present in the water, as the dominant reaction of the ozone-based ammonia-oxidation in seawater requires the previous formation of OPO as intermediates. The oxidation of ammonia in seawater by ozone is basically a bromide-catalyzed reaction with nitrogen gas as end product, enabling an almost complete removal of ammonia-nitrogen from the aquaculture system. Results further show that pH has no effect on the ozone-based ammonia oxidation in seawater. Unlike in freshwater, an effective removal of ammonia even at pH-values as low as 6.5 has been shown to be feasible in seawater. However, as the predominant reaction pathway involves an initial accumulation of OPO to toxic amounts, we consider the ozone-based removal of ammonia in marine RAS as risky for animal health and economically unviable. 相似文献
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It is frequently assumed that, in general, combinations of antibiotics and similar chemotherapeutic agents are more efficient than the single chemotherapeutic, and that they can be combined without disadvantages for the activity of the single component. However, the specific properties of the combined substances, such as their antimicrobial spectrum and resistance, their pharmacokinetics and side effects, as well as their physical properties and formulation, have an enormous impact on the activity of combined chemotherapeutics. They may lead to an advantageous, but also to an indifferent or diminished activity of the combination in patients. Some of the important requirements for an advantageous combination of antibiotics and similarly functioning compounds will be reviewed and ways of avoiding mistakes are described. 相似文献
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Kentaro Sakamoto Ken Touhata Michiaki Yamashita Akihide Kasai Haruhiko Toyohara 《Fisheries Science》2007,73(3):675-683
ABSTRACT: Cellulose digestion by Corbicula japonica was investigated according to the hypothesis that without any symbiotic aid, this organism can utilize cellulose as a carbon source. Enzymatic studies revealed the complete cellulase activity of this species, and molecular cloning resulted in the isolation of cDNA with an ORF encoding a 596-amino-acid protein that shares significant homology with abalone and termite cellulases with an amino acid identity of 52.2% and 50.5%, respectively. The isolated cellulase had a carbohydrate-binding module at the N-terminal region that was also reportedly present in abalone cellulase, and its mRNA were specifically expressed in the digestive gland. These findings strongly support the assumption that C. japonica has an endogenous cellulose, as well as abalones and termites. It is further believed that C. japonica plays an important roll in decomposing cellulose, and consequently contributes to the carbon-cycle in the aquatic environment, as termites do in terrestrial forests. 相似文献
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When is a fisher (not) a fisher? Factors that influence the decision to report fishing as an occupation in rural Cambodia 
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下载免费PDF全文 In the developing world, the majority of people who fish in inland areas do so primarily for subsistence needs. This suggests that survey or census questionnaires which collect information concerning the occupations of respondents will underreport the number of people who fish, and corollary to this, misrepresent dependence on fishing as a support service for food and supplemental income. This study uses the results of a household survey conducted in 37 villages across Cambodia to quantify the amount of fishing that is done by inland fishers who do not report fishing as a primary or secondary occupation. The study also identifies the household characteristics which influence the decision of an individual who fishes to report fishing as an occupation. Fifty‐eight percent of households whose members engaged in fishing activities did not report fishing as an occupation. Individuals whose household owned farmland, earned off‐farm income and fished primarily for subsistence needs were significantly less likely to report fishing as an occupation. When assessing the importance of fishing to inland rural communities for the purposes of rural planning and policy development, relying solely on census‐style occupation or employment data will misrepresent the contributions of subsistence fishing to household welfare. 相似文献
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M. F. TATNER 《Journal of fish diseases》1991,14(3):395-400
Abstract. Extracellular product (ECP) antigens of Aeromonas salmonicida were modified in an attempt were tested on an antigen-induced proliferation assay, for the ability to induce antibodies as measured by dot blot dot assay and as vaccines in vaccination/challenge trials. Modifications tested included particularization on to polystyrene beads, coating on to sheep red blood cells, mixing with BCG vaccine as adjuvant, and attachment to the T-independent carrier Fieoll. The only modification that resulted in increased protection levels was the particularization on to polystyrene beads. 相似文献
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D. K. O. Chan 《Fish physiology and biochemistry》1986,2(1-4):179-193
The cardioventilatory performance of the Japanese eel,Anguilla japonica, was evaluated during acute exposure to hypoxia. The eel became an oxygen conformer as ambient PO2 fell below the critical value of 110 mmHg. Although arterial and venous PO2 also fell progressively, the arterial O2 content remained constant down to an ambient PO2 of about 60 mmHg. Arterial blood O2 saturation was maintained at 85% even at 40 mmHg. The increase in the supply of O2 to the animal during hypoxia was due to a combination of adaptive adjustments: (1) an increase in ventilation: perfusion ratio brought about mainly be bradycardia; (2) an increase in respiratory exchange surface area which was manifested as an increase in branchial blood transit time and quantified as a rise in transfer factor, water-blood overlap coefficient and utilization (%); (3) an increase in blood O2 affinity and capacitance coefficient as a result of respiratory alkalosis and Bohr-Root shift and a decrease in haemoglobin allosteric modulator (GTP, ATP) concentrations in the RBC. These factors together helped to increase the efficiency of O2 transfer across the gills. 相似文献
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Anaerobic Treatment of Brackishwater Aquaculture Sludge: An Alternative to Waste Stabilization Ponds
Natella Mirzoyan Ryan Christopher McDonald Amit Gross 《Journal of the World Aquaculture Society》2012,43(2):238-248
Environmental pressure, land utilization, and economic feasibility have resulted in the development of recirculating aquaculture systems (RAS). For many RAS, sludge is collected and washed from the system to waste stabilization ponds (WSPs). However, disposal of brackishwater aquaculture sludge into WSP is often prohibited because the high salinity can interfere with treatment. Moreover, there are problems associated with WSPs because of elevated salt content, such as the common practice of reusing treated water and land application of stabilized sludge. We tested and compared the treatment of brackishwater aquaculture sludge in an upflow anaerobic sludge blanket (UASB) reactor as an alternative to a WSP. In UASB, wastewater flows upward through a blanket of granular sludge and is treated by anaerobic micro‐organisms. Reduction in organic matter and 5‐d biochemical oxygen demand by 97 and 91%, respectively, was achieved in a UASB as compared to corresponding reductions of 22 and 41% in a WSP. During the UASB digestion process, methane is produced and recovered. Overall, a reduction in potential environmentally harmful factors such as salinization, land requirements, greenhouse gas emissions, as well as transportation costs are achieved, making the UASB reactor an attractive possible alternative for saline aquaculture sludge management. 相似文献
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Ya-Xiang Bai Gui-Juan Yang Yu-Cai Hu Min Qu 《Journal Of Aquatic Food Product Technology》2013,22(3):238-247
Electrohydrodynamic (EHD) drying was tested as an improved dehydration method for scallop muscle. The scallop muscle was dried in an EHD drying system at 15°C, in an oven at 60°C, and in ambient air at 15°C. The energy consumption of EHD and oven drying, as well as the shrinkage rate, water absorption, solid loss, and sensory properties such as color and anti-crushing durability of the dried scallop muscle were measured. Results showed that the drying rate of scallop muscle significantly improved using the EHD drying system. Under a 45 kV voltage, the drying rate of EHD is 7 times higher compared with that of air drying in the 1st h. Compared with oven drying, EHD drying was more efficient in terms of energy saving. Furthermore, EHD drying cost only 28.67% of the electric energy required for oven drying. The dried scallop muscle by EHD had better sensory qualities and higher anti-crushing durability. EHD drying is very advantageous and can be used as a substitute to the traditional drying method. 相似文献