养殖密度、水质和分级对水泥池鱖鱼苗种培育的影响

Effects of stocking density,water quality and multi-stage rearing strategy on Siniperca chuatsi fry culture

为研究养殖密度、水质和分级对水泥池鳜苗种培育的影响，以翘嘴鳜鱼苗（体长0．7～1cm）为对象，在不同密度下投喂麦瑞加拉鲮进行试验。结果表明：（1）小规格苗种（〈2．5cm）的放养密度宜在4000尾／m^3左右，大规格苗种（2．5～6．5cm）的放养密度不宜超过800尾／m^3。（2）养殖水体中氨氮和亚硝酸盐的浓度均与鳜鱼苗养殖密度成显著正相关，水泥池中进行鳜鱼苗种培育不宜密度过高，密度越高，疾病暴发的风险越大。（3）分级过筛选取鳜苗体长为2～3、5-6、8-9cm时的3个节点进行，保持饱食投喂，能较好地提高鳜鱼苗种的整齐度，降低残食率，提高成活率。

To study the effects of stocking density, water quality and multi-stage rearing strategy on fry culture of Siniperca chuatsi in concrete tanks, different stocking densities and three stage rearing were designed in the experiment and the water quality was detected. S. chuatsi was fed with live fry of Cirrhinus mrigala. The results showed that, the proper stocking density of S. chuatsi fry at small size （ 〈 2.5 cm ） was 4 000 individuals/m^3, while no more than 800 individuals/m3 at a larger size （ 2.5-6.5 cm ） . There was a positive relationship between the concentrations of NH4^＋-N, NO2^--N and the stocking density. The higher was the stocking density of fry culture of S. chuatsi, the more diseases came up. The difference of body size became wider when the fry grew to 2-3cm, 5-6 cm, 8-9 cm. Three-stage rearing could effectively increase fry size uniformity and improve the survival rate significantly.