【作者】 张学振；

【导师】 王明学；

【作者基本信息】 华中农业大学 ， 水产养殖， 2003， 硕士

【摘要】 在循环水系统中繁育南方鲇苗种，经培养熟化，生物固定床滤材上形成致密均匀、丰厚饱满的生物膜，膜上含有较丰富的硝化细菌、芽孢杆菌、光合细菌等微生物，且形成以绿藻门、裸藻门为主水色清新的浅黄绿色藻相。经生物固定床滤器处理后，养鱼用水溶氧（DO）丰富、氨氮（NH₄⁺（NH₃）-N）和亚硝态氮（NO₂^--N）含量降低，化学耗氧量（COD）减少，保证育苗用水水质优良。对循环水试验池WT、pH、DO、COD、NH₄⁺（NH₃）-N、NO₂^--N等理化指标进行检测，结合孵化率和幼苗的生长等情况，对生物固定床滤器繁育南方鲇苗种的效果试验作出讨论和评价。 1．试验池中水质优良：pH稳定，溶氧较丰富（不低于5mg／l），氨氮、亚硝态氮含量降低，化学耗氧量也相应减少，均优于对照池各项水质指标，并存在显著性差异。利用循环水固定床滤器净化水质效果明显：氨氮、亚硝态氮、化学耗氧量平均去除率分别为31％、20％、27％。 2．试验池育苗效果显著，受精卵的孵化率高（平均为89.67％），开口率好（平均为82.0％），鱼苗生长速度快，至试验结束时测得鱼苗平均体长为42.18mm，日平均增长2.41mm，平均体重为317.33mg，日平均增重20.99mg。体长、体重与日龄的关系方程式分别为：L=1.0709+2.8044T（r=0.9966，n=15），W=0.3892T^2.4797（R²=0.9993）；体长与体重的关系式为：W=0.0119L^2.7149（R²=0.9956）。 而对照池鱼苗孵化率平均为74.0％，开口率72.0％，出苗17850尾。平均体长为33.77mm，日平均增长1.84mm，平均体重为259.86mg，日平均增重17.15mg。苗种生长符合方程L=2.6432+2.1457T（r=0.9961 n=15，），W=0.3025T^2.4986（R²=0.9989，n=15），体长体重的关系式为胆0.0056L^3.0212（R²=0.9964）。 3．出苗率高，试验池平均鱼苗存活率为24863尾，而对照池出苗17850尾，试验池比对照池高出39.29％。 4．采用本系统繁育南方鲇苗种，不但产量高，而且节约用水，节省能源，经济效益高。更多还原

【Abstract】 Fries of Silurus meridionalis were propagated and reared in recirculation system. After incubation, a compact and plump biological film was well distributed in the material on the fixed bed biofilrter. There were profound nitrofication bacteria, bacillus and photosynthetic bacteria and some other microorganisms on the film. The algal community was mainly consist of chlorophytes and euglenophytes, which made the water take a clear green-yellowish look.After treated by fixed bed biofilter, the water contained profound dissolved oxygen (DO), lower NH/(NH3)-N, NO2--N and COD. Thus the toxic impacts of NH4+(NH3)-N and NO2~-N on the fertilized eggs and fries of Silurus meridionalis was diminished. Good water quality was available for fry rearing. The effects of fixed bed biofilter on Silurus meridionalis fry rearing were evaluated on the basis of the detecting of pH, DO, COD, NH4+(NH3) -N and NO2~-N, etc and observation of incubating rates and growth character of fries.1. The good water quality was achieved in experimental pools. They had steady pH values, relatively profound DO (not less than 5 mg l-1), lower NH4+-N and NO2-N, decreased COD. All these characteristics were superior to the control pool. There was significant difference between experimental pools and control pool. The effects of fixed bed biofilter on water purgation were pronounced. The average removal rates of NH4+(NH3) -N, NO2-N and COD were 31%, 20% and 27%, respectively.2. The effects on fry rearing were obviously positive too. High fertilizing rate (averaged 89.67%) and feeding rate (averaged 82.00%) were obtained. Great growth rate of fries in experimental pools was also observed. At the end of four-week experiment, the mean body length of the fries was 42.18 mm, with an average daily growth of 2.41 mm; the mean body weight reached 317.33 mg with an average daily gaining of 20.99 mg. The growth equations are the follow: L = 1.0709 + 2.8044T(r = 0.9966, n = 15), W= 0.3892L2.4797 (r = 0.9993). The relationship between body weight and body length is W = 0.0119L2.7149 (r = 0.9956).On the contrary, the fertilizing rate (averaged 74.0%) and the feeding rate (averaged 72.0%) of the control pool were obviously lower than experimental pools. At the end of four-week experiment, the mean body length of the fries of the control pool was 33.77 mm, with an average daily growth of 1.84 mm; the mean body weight reached 317.33 mg with an average daily gaining of 17.15 mg. The growth equations are as the follow: L=2. 6432 +2.14577 (r = 0.9961, n = 15), W= 0. 3025T2.4986 (R2 = 0. 9989, n = 15). The relationship between body weight and body length is W=0. 0056L3.0212 (R2=0. 9964).3. Averagely 24863 fries were obtained in experimental pools, which was 39.29% higher than the control pool (17850 fries) .4. The propagation system can provide great fry population and consume less energy and water resource, thus greater economic benefit can be achieved.更多还原