不同盐度预处理后Ⅰ龄暗纹东方鲀的摄食、生长和饲料利用

通过4周的生长实验，研究了Ⅰ龄暗纹东方(8235±297g)在不同盐度预处理后的摄食、生长和饲料利用情况。结果显示:35‰的预处理盐度对暗纹东方的生长有抑制作用，当这种盐度胁迫解除后，暗纹东方的生长表现出明显的补偿现象。本实验中摄食率随前处理盐度的升高而增加，变化范围为183%-251%，特定生长率亦随前处理盐度增加而增加，即由083%增加到128%，饵料系数则随前期盐度实验中盐度的增加而降低，由167降至147。在盐度预处理实验及淡化养殖条件下的特定生长率除8‰外有显著差异。  

FOOD INTAKE, GROWTH AND FEED UTILIZATION OF PUFFERFISH (TAKIFUGU FASCIATUS) AFTER DIFFERENT SALINITY PRETREATMENTS

A 4-week trial was conducted to assess the further effects of salinity on growth and feed utilization of pufferfish Takifugu fasciatus (82.35±2.97g). The fish were transferred to freshwater directly after reared in 8‰, 18‰ and 35‰ salinity for more than 2 months. Triplicate groups of each treatment were fed practical diets with 50.5% protein (dry matter) to satiation. The growth, food intake and food conversion ratios of pufferfish were investigated and also compared results between present study and prior salinity experiment. The results indicated that high salinity (35‰) could suppress the growth of pufferfish while compensatory growth was observed when fish were free from salinity stress. Food intakes increased with prior experimental salinity and its range was 1.83%-2.51% and there were significant differences among treatments (P0.05); Specific growth rations exhibited the same tendency as food intake and increasing from 0.83% to 1.28% and there also showed significant difference; however, food coefficient decreased with prior salinity and from 1.67 to 1.47. Comparison between present SGR in freshwater and pre-experiment SGR in corresponding salinity showed significant differences except the fish in low salinity (8‰) of prior trail. The results observed in the pre-and present trials suggest that 1-year old pufferfish growth fast and scarcely suffer disease, therefore, 8‰ salinity could be assumed as suitable environment for this species in the stage.