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1.
苏应兵  廖咏玲  杨代勤  谢耀 《安徽农业科学》2011,39(35):21822-21823,21828
[目的]了解温度对泥鳅仔鱼孵化和仔鱼活力的影响。[方法]在不同温度(18、21、242、73、0和33℃)下,研究泥鳅受精卵的培育周期、孵化周期、孵化率和畸形率,对初孵的泥鳅仔鱼进行耐饥饿试验,测定其不投饵存活系数(SAI)。[结果]当温度为18~33℃时,泥鳅受精卵的培育周期和孵化周期随温度的升高而缩短。当温度为18℃时,泥鳅受精卵的培育周期和孵化周期最长,分别为39.43和10.13 h。当温度为21~27℃时,受精卵孵化率达80%以上,且初孵仔鱼的畸形率较低。当温度为18~30℃时,初孵仔鱼在24 h和48 h存活率都相对较高。不投饵存活系数(SAI)随温度的增长呈先升后降的变化趋势。当温度为24℃时,仔鱼的SAI值最高(27.01)。[结论]泥鳅受精卵孵化的适宜温度为21~27℃,仔鱼生存的适宜温度为21~24℃。  相似文献   

2.
春季采用全龄适当提高蚕的幼虫饲育温湿度、稚蚕期饲给适熟偏嫩桑叶、眠中不降低温度、各龄响食前后提高 1.5℃温度、控制日眠等方法饲养春用蚕品种。结果表明 ,龄期经过缩短 2d左右 ,以 10g蚁量为单位计算 ,用桑量比对照节省 10 %以上 ,劳力节约 2~ 3个工时。这不但降低了饲育成本、提高了经济效益 ,而且蚕的体质、茧量、茧质、蛾产卵量、良卵率、孵化率与对照相比均有不同程度的提高且无生种发生 ,原种繁育普通种对后代化性、眠性均无不良影响  相似文献   

3.
[Objective] The dynamic change of heterebacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp. [Method] The hcterobacteria, vibrios and pathogenic vibrio parahaemolyticus were monitored in larvae industrialized cul-ture system. [Result] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were the most in fertilized eggs of shrimp but the least in naupli-us, then their number would increase with growth. During whole rearing period, both heterobscteria in larvae, vibrios in water would increase by one order of magnitude, while both vibrios in larvae and heterobacteria in water would increase by two orders of magnitude. There were many heterohacteria and vibri-os but few vibrio parahaemolyticus in living bait. The correlation coeffcients between larvae and heterobacteria and vibrios in water were 0.704 and 0.840 in culture system respectively, while the correlation among heterobacteria, vibrios in living bait and larvae, water were weak or negative. [Conclusion] There was a dynamic relation between water and larvae in rearing period, and restrictly control of culture condition would restrain the occurrence of disceae caused by vibrio parahaemolyticus, besides that bacteria number in bait was not obviously correlated with bacteria nubmer in culture system.  相似文献   

4.
[Objective] The dynamic change of heterobacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp.[Method] The heterobacteria,vibrios and pathogenic vibrio parahaemolyticus were monitored in larvae industrialized culture system.[Result] The heterobacteria,vibrios and pathogenic vibrio parahaemolyticus were the most in fertilized eggs of shrimp but the least in nauplius,then their number would increase with growth. During whole rearing period,both heterobacteria in larvae,vibrios in water would increase by one order of magnitude,while both vibrios in larvae and heterobacteria in water would increase by two orders of magnitude.There were many heterobacteria and vibrios but few vibrio parahaemolyticus in living bait.The correlation coefficients between larvae and heterobacteria and vibrios in water were 0.704 and 0.840 in culture system respectively,while the correlation among heterobacteria,vibrios in living bait and larvae,water were weak or negative.[Conclusion] There was a dynamic relation between water and larvae in rearing period,and restrictly control of culture condition would restrain the occurrence of disease caused by vibrio parahaemolyticus,besides that bacteria number in bait was not obviously correlated with bacteria nubmer in culture system.  相似文献   

5.
以异养菌、弧菌、副溶血弧菌为监测对象,对中国对虾的工厂化育苗进行实时监测,探寻育苗过程中细菌的动态变化规律,为对虾健康养殖提供科学依据。  相似文献   

6.
研究结果表明,春制越年家蚕卵丝乙胚子冷藏处理后,其实用孵化率〉92.3%蚁蚕绝食致半数时数≥110h,不良卵发生率〈10%,发病率〈8.6%,茧质优良,产量平稳,在有效冷藏期限内随时出库催青饲育均安全可靠。  相似文献   

7.
[Objective] The dynamic change of heterobacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp.[Method] The heterobacteria,vibrios and pathogenic vibrio parahaemolyticus were monitored in larvae industrialized culture system.[Result] The heterobacteria,vibrios and pathogenic vibrio parahaemolyticus were the most in fertilized eggs of shrimp but the least in nauplius,then their number would increase with growth. During whole rearing period,both heterobacteria in larvae,vibrios in water would increase by one order of magnitude,while both vibrios in larvae and heterobacteria in water would increase by two orders of magnitude.There were many heterobacteria and vibrios but few vibrio parahaemolyticus in living bait.The correlation coefficients between larvae and heterobacteria and vibrios in water were 0.704 and 0.840 in culture system respectively,while the correlation among heterobacteria,vibrios in living bait and larvae,water were weak or negative.[Conclusion] There was a dynamic relation between water and larvae in rearing period,and restrictly control of culture condition would restrain the occurrence of disease caused by vibrio parahaemolyticus,besides that bacteria number in bait was not obviously correlated with bacteria nubmer in culture system.  相似文献   

8.
试验研究结果显示,春制越年家蚕卵乙胚子冷藏处理后的F1杂交家蚕种,其实用孵化率>923%,蚁蚕绝食致死半数时数≥110h,不良卵发生率<10%,发病率<86%,茧质优良,产量平稳。在有效冷藏期限内随时出库催青饲育均安全可靠  相似文献   

9.
本文根据油松毛虫幼虫转移生境的特性,将其越冬过程分解为上树阶段和下树阶段.首先通过主成分分析,寻找出影响越冬幼虫种群数量变动的关键因子主要是越冬幼虫生境的温度和空气中的相对湿度.在此基础上,通过主成分回归建立数学模型,预测越冬幼虫种群数量,为制定油松毛虫防治策略提供准确的虫情报告.  相似文献   

10.
香蕉果实乙烯受体基因克隆及其表达特性   总被引:2,自引:0,他引:2  
 【目的】分析香蕉果实成熟及贮藏冷害下乙烯受体基因的表达特性,探讨热处理(38℃,3 d)提高果实耐冷性与乙烯受体基因表达的关系。【方法】根据已报道的ETR基因的氨基酸保守序列设计引物,以香蕉果皮总RNA为模板,利用RT-PCR方法克隆香蕉的ETR cDNA,采用Northern杂交分析该基因的表达特征。【结果】香蕉果实在自然成熟进程中,两个基因在果皮和果肉中呈现不同的表达模式:果皮和果肉中Ma-ETR1的表达随果实成熟而逐渐减弱,而Ma-ERS3的表达仅在果实成熟后期略有增强;外源丙烯处理和38℃高温抑制果皮和果肉中Ma-ETR1的表达,却促进了Ma-ERS3的表达;低温促进果皮中Ma-ETR1和果肉中Ma-ERS3的表达,而38℃热处理3 d后则能抑制果皮中受低温诱导的Ma-ETR1表达的增强。【结论】外源丙烯和38℃高温正调控Ma-ERS3表达,负调控Ma-ETR1表达;38℃热处理3 d提高采后香蕉果实耐冷性与抑制低温诱导的果皮中Ma-ETR1表达的增强有关。  相似文献   

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