Abstract:Abstract: Dissolved oxygen (DO) in water is an important environmental factor for fish. Herein, growth and digestive enzyme activities of juvenile sweet fish (Plecoglossus altivelis) were analyzed under different levels of hypoxia stress. The results showed that the growth of larval P. altivelis was suppressed. The body weights of the two hypoxia stress groups (DO=4.5 mg/L and 3.0 mg/L, respectively) were both significantly lower than that of the control group (DO=7.5 mg/L) (P<0.05), losing 10.89% and 20.73%, respectively, as compared with the control group at day 21. During the stress period of day 0~7, the two experimental groups showed negative growth (-2.30% and -4.78%, respectively) on body weight, while the control group showed positive growth (21.31%). After that, the growth of fish in the two experimental groups resumed and the weight gain rates were higher than that of the control group during day 7~14, showing compensatory growth. During day 14~21, the weight gain rate of DO=4.5 mg/L group was similar to that of the control group, while the weight gain rate of DO=3.0 mg/L group was slightly lower than that of the control group. Furthermore, the activities of amylase, pepsin and lipase were significantly decreased during hypoxia stress (P<0.05), while the activity of trypsin showed no significantly different changes compared with the control group (P>0.05). Pepsin was the most sensitive to hypoxia among these four digestive enzymes. After 21 days of hypoxia stress, the pepsin activities in DO=4.5 mg/L and DO=3.0 mg/L groups were only 58.40% and 62.34%, respectively, of the control level, while the amylase activity was restored to the same level as the control, and the lipase activity also got some recovery after the fish lived in low oxygen environment for a period of time. Altogether, hypoxia could reduce the digestive enzyme activity and restrain the growth of juvenile sweet fish, and the fish also showed some adaptability to hypoxia such as compensatory growth and partial recovery of digestive enzyme activities.
引用本文:
石华洪, 苗 亮, 李明云, 徐玉敏, 张 浩, 方 磐, 陈晓升, 陈政榜, 黄翔晖. 水体低氧对香鱼幼鱼生长和消化酶活性的影响[J]. 生命科学研究, 2019, 23(6): 469-475.
SHI Hua-hong, MIAO Liang, LI Ming-yun, XU Yu-min, ZHANG Hao, FANG Pan, CHEN Xiao-sheng, CHEN Zheng-bang, HUANG Xiang-hui. Effects of Hypoxia on Growth and Activities of Digestive Enzymes of Juvenile Sweet Fish (Plecoglossus altivelis). Life Science Research, 2019, 23(6): 469-475.