温度对施氏鲟幼鱼摄食、生长和肠道消化酶活性的影响

摘要

研究不同养殖温度(15℃、18℃、21℃、24℃、27℃)对施氏鲟(Acipenser schrenckii)幼鱼摄食、生长和肠道消化酶活性的影响.结果表明,在15～24℃范围内,幼鱼的特定生长率(SGR)和相对增重率(RWG)随温度的升高而显著增加(P＜0.05),均在24℃时达到最高值；随着温度升高,其饵料系数(FC)先降低后升高(P＜0.05),且在24℃时达到最小值；此外,摄食率(FR)随着温度的升高而显著升高(P＜0.05),其不同温度组的生长速度由高到低依次为24℃、21℃、27℃、18℃、15℃组.温度对幼鱼前肠蛋白酶活性影响显著,24℃组和27℃组前肠的蛋白酶活性显著低于15℃组(P＜0.05),而温度对中肠和后肠蛋白酶活性则无显著性影响(P＞0.05)；温度对幼鱼肠道脂肪酶活性无显著性影响(P＞0.05),各温度组前肠脂肪酶活性均高于中肠和后肠；温度对幼鱼肠道淀粉酶活性无显著性影响(P＞0.05).综合以上结果认为,施氏鲟幼鱼快速生长的适宜温度范围为21～24℃,在此温度范围内施氏鲟幼鱼可获得最大生长率和存活率.%The juvenile Acipenser schrenckii were fed at different temperature (15℃, 18℃, 21℃, 24℃, 27℃) to study the effects of water temperature on feeding, growth and activities of digestive enzymes using morphological and biochemical methods. The results showed that, the specific growth gain (SGR) and relative weight gain (RWG) significantly increased with the increasing temperature between 15℃-24℃ (P＜0.05), and reaches the maximum at 24℃. The feed conversion ratio (FC) decreased significantly and reached the minimum at 24℃, and then greatly increased. In addition, the feed ration (FR) increased remarkablely with the temperature increasing (P＜0.05).The growth rate in the different temperature group were in the order of group 24℃＞21℃＞27℃＞18℃＞15℃. The water temperature had significant effects on the protease activity in the foregut(P＜0.05), the protease activity in the foregut of the group 24℃ and 27℃ were notablely lower than the group 15℃ (P＜0.05), and the water temperature had no striking effects on the protease activity in the midgut and hindgut(P＞0.05). The temperature had no striking effects on lipase activity in intestinal tract (P＞0.05), and the lipase activity of midgut was higher than the hindgut and foregut in every temperature group. The temperature had no striking effects on amylase activity in intestinal tract (P＞0.05), and the amylase activity were in the order of midgut > hindgut > foregut. Taken together, the growth rate was fastest in the group 24℃, but the activities of intestinal digestive enzyme were lower than the group 21℃. The optimal growth temperature range is 21℃-24℃ for juvenile Acipenser schrenckii. In the temperature range juvenile Acipenser schrenckii can reaches the maximum growth rate and survival rate.