软颗粒饲料与鲜杂鱼糜对大黄鱼养殖水质的影响

Influence of Soft Pelleted Diet and Fresh Trash Fish Surimi on Water Quality in Large Yellow Croaker(Pseudosciaena crocea)Culture

在水温18.0～21.0℃、盐度21.0～25.8下,给平均体质量为280.0g/尾的大黄鱼投喂软颗粒饲料（试验组）和鲜杂鱼糜（对照组）,评价两种饲料对环境影响,其中试验组、对照组各设3个平行,空白组（不放鱼也不投料,仅有砂滤海水）不设平行。试验结果表明,试验组和对照组养殖水中总氮、总磷和化学需氧量含量均与空白组差异显著（P〈0.05）,对照组最高,空白组最低;试验组与对照组水中总磷差异不显著（P〉0.05）,而总氮和化学需氧量含量均差异显著（P〈0.05）;试验组水中沉积物总量显著少于对照组（P〈0.05）;试验组水中沉积物中总氮、总磷总量均显著少于对照组（P〈0.05）。软颗粒饲料对养殖环境的影响显著小于鲜杂鱼糜,可在海水鱼类网箱养殖中应用推广。

Juvenile large yellow croacker Pseudosciaena crocea with initial average body weight of 280.0g were fed soft pelleted diet（treatment group）and fresh trash fish surimi（control group）at water temperature of 21.0—18.0℃,and a salinity of 25.8—21.0with triplication to evaluate the effects of different diets on water quality,meanwhile no fish was stocked in a blank tank（blank group）filled with only sand filtered seawater.The results showed that there were significant differences in contents of total nitrogen（TN）,total phosphorus（TP）,and chemical oxygen demand（COD）in water in treatment group and blank group（P〈0.05）,the peak in control group,and the minimum in blank group.There was no significant difference in TP contents between the treatment group and control group（P〉0.05）,while there were significant difference in TN and COD contents（P〈0.05）.There was significantly lower total sediment in the treatment group than that in the control group（P〈0.05）;there were significantly lower TN,and TP contents in the treatment group than that in the control group（P 0.05）,indicating that soft pelleted diet shows much less effects on environment than the fresh trash fish surimi does,and is widely used in marine fish cage cultivation.