共查询到19条相似文献,搜索用时 62 毫秒
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澳洲宝石鱼(Jade perch)学名为高体革鯻Scottumbazvoo。我国现存的鯻科种类全为海水生栖,在我国南方沿海有分布。澳洲宝石鱼是分布在澳大利亚爱尔湖、布罗-本凯那水系的淡水本土鱼类,澳大利亚鯻科鱼类有22种,宝石鱼是其中极具养殖前途的一种。宝石鱼具有体形优美、营养丰富及生长速度快、抗病力强等优点。 相似文献
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水产养殖中病原生物的耐药性及其防止对策 总被引:3,自引:0,他引:3
随着水产养殖业的迅速发展,高密度集约化养殖方式的全面普及,鱼虾贝藻病害的发生也越来越频繁。药物防治,以其快速、方便、准确、有效的特点而广泛地为养殖者所接受、采用。然而,病原生物在不断受到化学药物袭击的条件下,通过产生解毒酶系改变体表张力、基因变异等作出不同程度的 相似文献
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循环流水水产养殖系统接种商品硝化菌的试验研究 总被引:5,自引:1,他引:4
与接种成熟滤料等方法相比,利用商品硝化菌接种生物滤器来源广泛,操作简便。本文使用一种商业上已取得一定成功的商品硝化菌液接种循环流水水产养殖系统试验模型的生物滤器。试验开始时定期接人20mL菌液(细菌含量1.5×10~10CFU·mL~(-1))以处理400g饲料产生的4.27mg·L~(-1)氨氮(TAN),12d后TAN浓度低于0.05mg·L~(-1),20d后NO_2~- -N浓度降至同样水平。在为期30d的检验期中,系统内养殖2.15kg·m~(-3)淡水白鲳,日喂饲率2%。期间养殖池TAN最大值0.465mg-L~(-1),最小值0.393mg·L~(-1),平均值0.427±0.019mg·L~(-1);NO_2~- -N最大值0.062mg·L~(-1),最小值0.038mg·L~(-1),平均值0.052±0.007mg·L~(-1);EC呈线性上升状态,每周增加32.8 μs·cm~(-1);而pH呈线性下降,每周降低0.24。系统结束时生物滤器含细菌8.65×10~6CFU·mL~(-1),水质除TP超标外,其余指标均符合我国淡水水产养殖水质标准,在2.1%~1.4%的日喂饲率下淡水白鲳日增重为1.91g,饲料系数1.164。 相似文献
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Marine recirculation aquaculture system (RAS) is a prominent technology within fish farming. However, the nitrifying bacteria in the biofilter have low growth rates, which can make the biofilter activation a long and delicate process with periods of low nitrification rates and variations in water quality. More knowledge on the microbial development in biofilters is therefore needed in order to understand the rearing conditions that favour optimal activation of the biofilters. In this case study, we investigated the activation of two biofilters in a marine RAS for Atlantic salmon post‐smolt associated with either high or low stocking densities of fish by monitoring the microbial communities and chemical composition. The results showed that the microbial communities in both biofilters were similar during the first rearing cycle, despite variations in the water quality. Nitrifying bacteria were established in both biofilters; however, the biofilter associated with low stocking density had the highest relative abundance of ammonia‐oxidizing Nitrosococcus (1.0%) and nitrite‐oxidizing Nitrospira (2.1%) at the end of the first rearing cycle, while the relative abundance of ammonia‐oxidizing Nitrosomonas (2.3%–2.9%) was similar in both biofilters. Our study showed that low fish stocking density during the first rearing cycle provided low and steady concentrations of ammonium, nitrite and organic load, which can stimulate rapid development of a nitrifying population in new marine RAS biofilters. 相似文献
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采用自行设计的抽屉式生物滤器应用于漠斑牙鲆(Paralichthys lethostigma)闭合循环水养殖系统,研究其对循环养殖水的处理效果及漠斑牙鲆的增重和饲料利用率的影响。结果表明:经过60 d的循环水养殖,漠斑牙鲆从初始时的(225.4±11.9)g增加到结束时的(337.5±10.3)g,增重率49.97%;试验饲料系数1.06,养殖密度24.1 kg/m3,成活率100%;抽屉式生物滤器对于NH4+-N、NO2--N和COD去除率分别为(10.61±1.88)%、(14.90±3.06)%和(16.11±1.70)%,可满足漠斑牙鲆养殖水体的水质要求。 相似文献
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本介绍了双层浮球式生物滤器在封闭循环式鲟鱼养殖生产中的应用情况。在一个120m^3水体,养殖密度19kg/m^3的鲟鱼循环养殖系统中,应用一套动力为4kw、处理能力为40T/h的BAF-40型双层浮球生物过滤设备进行养殖水体的循环使用处理。在生产过程中,对养殖水体的pH、DO、COD、悬浮物、氨氮、亚硝酸盐、硝酸盐等水化学指标进行了监测,并对鲟鱼在养殖过程中不同阶段的生长情况进行了测量。结果表明,在水体循环周期为1次/3h,换水周期为1次/周的条件下COD≤15mg/l、氨氮≤1mg/l、亚硝酸盐≤0.13mg/l、硝酸盐≤24mg/l,经12月养殖,成活率为98%,增重10倍。应用表明BAF-40型双层浮球式生物滤器可完全满足鲟鱼工厂化养殖生产的要求,确保鲟鱼养殖水体的水质和鱼类生长环境,达到良好养殖效果。 相似文献
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利用自制的硝化细菌菌剂促进移动床生物膜反应器(Moving bed biofilm reactor,MBBR)的挂膜启动,分析不同载体氨氮负荷、碳氮比条件下反应器运行状况,并进一步进行了实验室模拟循环水养殖草金鱼实验。结果显示,利用自制硝化菌剂能够完成整个移动床反应器的启动过程,在接种15 d后使循环出水氨氮稳定在1 mg/L以下。单位体积载体氨氮负荷实验表明,MBBR能够在100 mg TAN/(L填料·d)条件下,使出水满足一般水产养殖水质要求(氨氮0.5 mg/L,亚硝氮0.1 mg/L)。进水碳氮比在1以内时MBBR能够稳定高效运行。在实验室模拟循环水养殖过程中,经菌剂强化的MBBR能维持循环出水氨氮低于0.5 mg/L,亚硝氮低于0.05 mg/L。 相似文献
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Kotaro Kikuchi Nakahiro Iwata Takeshi Furuta Toyoki Kawabata Toshiharu Yanagawa 《Fisheries Science》2006,72(5):1042-1047
ABSTRACT: Two feeding experiments were conducted to elucidate growth performance of tiger puffer in a 10 m3 water volume closed system. In experiment 1, 1000 fish of 3.5 g average body weight were fed tiger puffer commercial feed twice daily to apparent satiation, 6 days a week for 224 days. Sand-filtered sea water was used and no water was exchanged during the rearing period. Immediately after cutting of lower teeth at day 112, daily feed consumption decreased greatly and 60 fish died in few days. Feeding rates recovered and then decreased gradually as nitrate levels increased from 600–1048 mg N/L. Fish grew to 343 g with 91% survival rate and 87% feed efficiency. Rearing conditions of experiment 2 were similar to experiment 1, except that culture water was exchanged to maintain the nitrate level less than 600 mg N/L during the 224-day experiment. Mortality and reduction of feed consumption occurred immediately after teeth cutting as was observed in experiment 1. Significant reduction of feed intake was not found during other rearing periods. Fish of 3 g grew to 303 g with 91% survival rate and 72% feed efficiency. 相似文献