论文部分内容阅读
研究了军曹鱼Rachycentron canadum幼鱼(初始体重10g左右)的日摄食节律及不同摄食水平条件下鱼体的化学组成、特定生长率和食物转换率,以此确立人工育苗过程中军曹鱼幼鱼的适宜投饵时间和和投饵水平。研究结果表明,军曹鱼幼鱼具有明显的昼夜摄食节律,摄食主要在白天进行,以早晨(06:00—08:00)和傍晚(18:00—20:00)最为活跃,形成一天中的2个摄食高峰,夜间基本不摄食。由此可见军曹鱼幼鱼的摄食节律属白天摄食偏晨昏性类型。在饥饿、3%、6%、9%和饱食(指日投饵干重占试验鱼初始体重的百分比)摄食水平条件下,军曹鱼幼鱼鱼体蛋白质和脂肪含量随摄食水平的增加呈增长趋势,在6%摄食水平组脂肪含量出现大幅下降,在3%—饱食摄食水平时蛋白质含量变化不明显。军曹鱼幼鱼的湿重、干重和蛋白质特定生长率均随摄食水平的增加呈减速增长趋势,两者间的关系表现为对数函数形式:SGRw=3.876 ln(RL+1)-3.716,SGRd=5.107 ln(RL+1)-5.24,SGRp=5.561 ln(RL+1)-5.609,9%和饱食摄食水平组特定生长率无显著差异;脂肪特定生长率随摄食水平的增加而线性增长:SGRL=1.731RL-7.702。食物湿重、干重、蛋白质和脂肪转换率随摄食水平的增加均呈先升后降的变化趋势,9%摄食水平组有最大值,约为最大摄食水平的70%。因此,军曹鱼幼鱼投饵应在白天进行,适宜投饵时间为早晨和傍晚2个摄食高峰期,这个生长阶段的军曹鱼幼鱼当投喂鳗鱼配合饲料时其适宜投饵水平约为最大摄食水平的70%。
The daily feeding rhythm of juvenile Rachycentron canadum (initial body weight about 10g) and the chemical composition, specific growth rate and food conversion rate under different feed levels were studied to establish the suitable castration of juvenile cobia juveniles Bait time and bait level. The results showed that juvenile cobia juveniles had obvious circadian rhythms. The feeding was mainly carried out in the daytime and was most active in the morning (06: 00-08: 00) and evening (18: 00-20: 00), forming 2 A feeding peak, the basic non-food at night. This shows that cobia juvenile feeding rhythm is partial daytime partial morning dusk type. Under starvation, dietary levels of 3%, 6%, 9%, and satiation (mean daily feed bait weight as a percentage of initial body weight of test fish), the protein and fat content of juvenile cobia juveniles increased with increasing feeding levels There was a significant decrease in fat content at 6% feeding level, but no significant change in protein level at 3% -saturation feeding level. The wet weight, dry weight and protein specific growth rate of juvenile cobia juveniles decreased with increasing feeding levels, the relationship between the two showed a logarithmic function: SGRw = 3.876 ln (RL + 1) -3.716, SGRd = 5.107 ln (RL + 1) -5.24, SGRp = 5.561 ln (RL + 1) -5.609,9%, respectively. There was no significant difference in the specific growth rate between the two groups. The specific growth rate of fat increased linearly with the increase of feeding level : SGRL = 1.731RL-7.702. The wet weight, dry weight, protein and fat conversion rate of food showed a trend of increasing firstly and then decreasing with the increase of food intake, and the maximum of 9% food intake group was about 70% of the maximum food intake. Therefore, juvenile cobia juvenile feeding should be carried out during the day, suitable feeding time for morning and evening 2 feeding peak, juveniles of this stage of growth of juvenile cole feeding eel feed adapted to feed the level of about the maximum feeding level Of the 70%.