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1.
牛坏死梭杆菌病对养牛产业造成了巨大危害,介绍了牛坏死梭杆菌的病原学特征、流行特征、发病特征、疫苗研究、预防治疗措施,对牛坏死梭杆菌感染的防治提供参考。  相似文献   

2.
本文综述了许氏平You的生态特征、摄食与生长、繁殖习性等生物学特征。介绍了亲鱼选择、人工培育及病害防治技术。  相似文献   

3.
海带种质特征   总被引:2,自引:1,他引:2  
系统地研究了海带(Laminaria japonica Aresch.)的种质特征。详细地描述了海带的形态构造、生活周期与繁殖、特殊物质及含量、鲜干比、同工酶、分子标记等方面特征,确定了海带物种特征的指标范围,为海带种质检测和鉴定提供了技术参考指标。  相似文献   

4.
凤眼莲的生态特征   总被引:11,自引:0,他引:11  
安鑫龙  李婷 《水利渔业》2007,27(4):82-84
凤眼莲一直是水产养殖、生态学、环境科学等多学科的研究对象,随着环境污染的加剧和凤眼莲造成的生态破坏日益严重,深入系统地研究其生态特征具有重大意义。从凤眼莲生物学特征、生态分布、植物体及其根分泌物组分、根际生物系统及其死亡引发的二次污染问题等5个方面,概括总结了凤眼莲的生态特征;这些特性既是利用凤眼莲进行污水净化、水产养殖、环境监测和美化环境的基础,同时又为其生态入侵等提供了可能,深入研究其生态特征是更好地利用和有效控制凤眼莲的理论基础。  相似文献   

5.
麦穗鱼生物学特性及繁殖技术研究   总被引:1,自引:0,他引:1  
观察研究了江西鄱阳湖流域麦穗鱼的形态特征、生活习性、食性以及繁殖习性等生物学特征,并对其繁殖技术进行了初步研究.  相似文献   

6.
本文报道了中外海参的资源状况及生物学特征,阐述了其生态分布的特点及品质特征,为海参的养殖、增殖、资源的开发、捕捞及加工提供了理论依据.  相似文献   

7.
为解决渔业养殖及转运自动计数要求,提出一种基于机器视觉的鱼类识别算法设计与程序编制,以证明使用数字图像识别分类技术的尺度不变特征变换SIFT及加速稳健特征SURF算法等可有效地检测与标注鱼类图像特征点。采用快速近邻匹配FLANN匹配算法测试了基于图像特征的鱼类旋转和泛化目标检测,得出SURF特征对个体检测效果好、SIFT特征对泛化目标检测效果优的结果。考察FLANN图像匹配碎片化特性、结合图像信息区域聚集实际、借鉴模板检测方法,设计了图像分割扫描及特征匹配的模板检测算法,并使用最大稳定极值区域MSER方法对识别结果进行冗余排除,达到能正确识别多目标鱼类的算法预设目标。研究发现,该算法及软件能成功识别图片中的多个鱼类目标,测试效果好,有较强的实用意义。  相似文献   

8.
本文综述了乌鳢的形态特征、生活、摄食和繁殖习性等生物学特征,详细介绍了乌鳢的人工繁殖苗种培育、成鱼养殖及鱼病防治技术。  相似文献   

9.
《畜禽业》2016,(11)
综述了猪巴氏杆菌病的病原特征、流行病学特点、临床表现和剖检特征,并和临床上相类似的疾病进行了鉴别诊断。对分离的病原进行了药敏试验,得出头孢噻呋、青霉素+链霉素高敏,指导临床用药,给该病的防控提供了依据。  相似文献   

10.
张青  王锡昌  刘源 《水产学报》2009,33(4):692-696
为探明鲢肉挥发性气味特征物质,通过顶空固相微萃取法提取和浓缩了鲢肉中的挥发性物质,并利用气相色谱质谱联用以及气相色谱〖CD*7/9〗嗅觉测量法对气味物质进行了定性分析及气味特征的评价。由8人组成的评价小组通过检测频率法进行嗅觉测量。结果表明,经GCMS分析鉴定得到了29种挥发性气味物质,主要是一些羰基类和醇类化合物,占了总挥发性物质的88%。通过检测频率分析法鉴定出12种化合物具有气味特征,表现为鱼腥、金属、青草、油脂氧化、蘑菇等特征。另外有4种未知物也显示了较强的风味特性,它们协同作用构成了鲢的特殊气味。  相似文献   

11.
Rainbow trout (Oncorhynchus mykiss) is one of the most popular aquacultured species in the world. Sustainable production of this fish at commercial scale is very important but requires maintaining good water quality throughout the total rearing period. The present study aimed to develop a rainbow trout production index in order to raise awareness about the conditions of the rearing environment, enhance production, and reduce losses. For this purpose, an intensive rainbow trout production system was selected as the study system. In this system, there were seven stations including (a) 3000 5-g fish, (b) 3000 25-g fish, (c) 3000 50-g fish, (d) 3000 100-g fish, (e) 3000 220-g fish, (f) 2000 350-g fish, and (g) 2000 830-g fish. The fuzzy inference system was used to develop the target rearing index. Water quality parameters involved in the variation in the rainbow trout rearing conditions were classified into three groups including un-ionized ammonia, nitrite, and nitrate, Alkalinity and phosphate, along with dissolved oxygen and linear velocity. For each group and condition of rearing, a separate fuzzy inference system was defined and the output of each fuzzy system was named I1, I2, I3. Finally, I1, I2, and I3 were considered as the inputs to a fuzzy system in order to evaluate their effects on the index of general rearing conditions (I). The results indicated that un-ionized ammonia, nitrite, nitrate, and phosphate had negative effects while dissolved oxygen, linear velocity, and alkalinity positively affected water quality and rearing index. Most of the decline in the rainbow trout rearing index was related to the effect of un-ionized ammonia, nitrite, and nitrate due to food decomposition. Therefore, intelligence feeding based on fish appetite through reducing food conversion rate and water pollution can improve rainbow trout production in this system. The index of rainbow trout production conditions reflects the type, amount, and effect of water quality pollutants on rearing conditions. Producers can use this information to reduce the negative environmental effects and improve the product quality.  相似文献   

12.
在半封闭式奥尼罗非鱼养殖池中投入饲料,探索养殖过程中鱼池沉积形成及其主要影响因子。试验结果表明:无论养鱼或未养鱼,投饲或不投饲,各池均发生不同程度的沉积;外源饲料输入量相同时,养鱼池新颗粒物生成量(干重)比未养鱼池大15.63%,而沉积量比未养鱼池小19.49%;无外源饲料输入时,养鱼池的沉积量比未养鱼池大75.76%;养殖系统内养殖对象与其所处环境的相互依存和相互制约对系统新颗粒物生成及沉积具有重要作用。  相似文献   

13.
塘鳢是淡水小型经济鱼类,江浙沪一带将其视为名菜,为发展特种小水产品,作者于1992~1995年进行了塘鳢养殖试验工作,取得了人工繁殖,苗种培育及成鱼饲养的成套经验,人工繁殖和苗种培育在20m^2的网箱中进行,鱼孵化率和苗种(夏花)成活率分别达到59.71%和71.03%,成鱼饲养采取池塘混养方式,在267m^2的池塘中经170天养成尾重20g以上的商品鱼18.25kg,成鱼饲养成活率为64.5%  相似文献   

14.
The influence of rearing conditions on Flavobacterium columnare infection of rainbow trout, Oncorhynchus mykiss (Walbaum), was studied experimentally in the laboratory and at a fish farm. In experiment I, the effect of parasitic infection on columnaris disease was studied using F. columnare carrier fish. The fish were exposed to Diplostomum spathaceum cercariae and a set of other stressors in order to induce clinical columnaris infection. Parasitic infection and other stressors failed to induce the disease. Disease occurred when the fish were challenged with F. columnare, but D. spathaceum infection did not enhance the severity of the infection. In experiment II, the influence of rearing density and water temperature was studied. Overall mortality was highest in fish at normal rearing density with high temperature (+23 degrees C). At low temperature (+18 degrees C) mortality was not affected by rearing density, but the transmission of columnaris disease was faster at normal rearing density at both temperatures. This supports the view that reduction of fish density could be used in prevention of columnaris disease especially if water temperature is high. Because the lower rearing density can also decrease the transmission of ectoparasites and penetrating endoparasites, it could be an efficient tool in ecological disease management.  相似文献   

15.
六线鱼人工育苗技术研究   总被引:2,自引:0,他引:2  
使用从海区采集和人工催产获得的六线鱼卵块1091g,孵化仔鱼11万尾,平均孵化率为56%,仔鱼经45~60天培育,育成全长2.5~4.0cm,鱼种1.83万尾,平均成活率24.4%,专家验收认为,育苗量,苗种规格及生长速度均处国内领先水平,对卵块收集,人工孵化,苗种生长,饵料系列,育苗病害,饵料生物培育等问题进行了研讨。  相似文献   

16.
A major concern in larvae production is a mass mortality caused by fish diseases. In larvae production, pumped‐up natural seawater filtered through a sand filter system is used for fish rearing, and microalgae and rotifer cultures. Here, we investigated the community structures of eukaryotic microbes, as well as total bacteria and vibrios, in various processed ‘waters’ used in a larvae production site. We observed that ultraviolet irradiation of seawater was effective to reduce not only total bacteria and vibrios but also eukaryotic microbes. Moreover, the community structures of total bacteria and vibrios in rearing waters for fish larvae were different from those in rotifer cultures fed with Chlorella, but rather similar to those in natural seawater and microalgae cultures. These results suggest that the bacterial community in rearing waters may originate mainly from natural seawater and then be selected by microalgae in rearing water. Overall, this study provides useful information for avoiding the risk of fish disease outbreaks in a larvae production site.  相似文献   

17.
The gut microbiomes of fish play important roles in host development, digestion and health. Evidence suggests that abiotic factors, such as diet and rearing temperature, could affect fish gut microbiota. In this study, the effect of dietary short‐chain fructooligosaccharides (scFOS) on turbot intestinal health, microbiota and digestive enzymes was investigated at two rearing temperatures: 15 and 20 °C. Four practical diets were supplemented with scFOS at 0, 5, 10 and 20 g kg?1. scFOS did not affect fish performance. PCR‐DGGE did not show differences in bacterial profiles between dietary treatments; however, the number of operational taxonomic units, richness and diversity were higher at 20 °C. Enzyme activities in the foregut were not affected by rearing temperature, while in the hindgut, enzyme activities were higher at 15 °C. Total alkaline protease, α‐amylase and lipase activities in the foregut were higher in fish fed 20 g kg?1 scFOS. Prebiotic supplementation had no effect on hindgut α‐amylase activity, while lipase activity of fish reared at 20 °C was higher in fish fed diet with 5 g kg?1 scFOS. No differences were observed in intestinal morphology. This was the first study to simultaneously evaluate the effect of dietary prebiotic level and rearing temperature on fish intestinal microbiota and health.  相似文献   

18.
1993-1994年利用鱼池、稻田改造成的池塘培育中华绒螯蟹扣蟹,采取塑膜围栏防逃、调节水质、科学投饵、抑制幼蟹性腺发育等技术,52亩鱼池改造池亩扣蟹105kg,规格100只/kg;595亩稻田改造池亩产扣蟹55kg,规格180只/kg。  相似文献   

19.
鱼类增殖放流站亲鱼池数值模拟研究   总被引:1,自引:0,他引:1  
增殖放流是目前普遍采用的减缓水利水电工程对鱼类影响的措施之一。亲鱼培育是增殖放流的关键环节,亲鱼培育池是增殖放流站中的关键设施。鱼池不同流速流场区域的形成与亲鱼池的结构型式、工艺尺寸、进出水流量等多种因素有关,特别是针对国内山区急流河段水电工程鱼类增殖放流站亲鱼池的数值模拟研究还处于空白。采用计算流体力学(CFD)方法对亲鱼培育池流场进行了模拟,从亲鱼适宜流速区间最大化的角度,通过标准k-ε模型对最常用圆形和矩形两种不同结构型式的鱼池进行三维建模,分析比较了不同结构尺寸圆形池与矩形池的水力学条件,建议优先采用圆形池作为亲鱼培育池的型式,最适宜径深比为6∶1~3∶1;场地紧张而采用矩形池时,适宜长宽比为4∶1~2∶1。除流场外,温度、溶氧、排污分布等其他环境因子对鱼类繁殖也有一定的影响。对于特定鱼类,应该根据其生物学特性,适时调整鱼池的流速,满足相关需求。研究结果丰富了国内鱼类增殖放流站亲鱼池结构设计内容,推荐的亲鱼池结构型式可为鱼类增殖放流站设计提供参考。  相似文献   

20.
Abstract. A preliminary study was conducted to assess the performance of the tilapia, Oreochromis spilurus (Günther), cultured in seawater cages at different stocking densities during the nursing and rearing phases. The stocking densities tested were 200, 400 and 600 fish/m3 during the nursing phase and 100, 200, and 300 fish/m3 during the rearing phase.
In both growth phases, no significant differences (P>0.05) were observed among the different stocking densities on the mean individual final weight, daily growth rate, feed conversion ratio and survival rate. Yields in cages stocked with 400 and 600 fish/m3 during the nursing phase, however, were significantly (P<0.05) higher compared with cages stocked with 200 fish/m3. No significant differences (P>0.05) were observed between 400 and 600 fish/m3. A density of 600/m3 is therefore considered to be optimum for the nursing phase.
Yields of cages during the rearing phase increased significantly (P<0.01) with the increase in stocking density. After grading the fish, however, no significant differences (P>0.05) were observed when only fish bigger than 150g were considered. The occurrence of exophthalmia (cataract) was observed in two of the four replicates at the highest stocking density (300 fish/m3) during the rearing stage. Therefore, a stocking density of 200 fish/m3 is considered optimum for the rearing phase.  相似文献   

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