低温胁迫对罗非鱼消化酶活性的影响

Effects of Low Temperature Stress on Digestive Enzyme Activity in Tilapia

本文研究12、15、20和25℃水温条件对埃及尼罗、美国尼罗和美国奥利亚罗非鱼消化酶活性的影响.结果表明,水温从25℃降到20、15和12℃,埃及尼罗罗非鱼前肠和后肠淀粉酶、肝脏淀粉酶和脂肪酶活性均显著降低（P＜0.05）,前肠蛋白酶活性在12℃显著降低（P＜0.05）;美国尼罗罗非鱼前肠蛋白酶和后肠淀粉酶活性显著降低（P＜0.05）,前肠淀粉酶、肝脏淀粉酶和脂肪酶活性在12℃显著降低（P＜0.05）;美国奥利亚罗非鱼前肠淀粉酶、肝脏淀粉酶和脂肪酶活性显著降低（P＜0.05）,前肠蛋白酶和后肠淀粉酶活性在12、15℃显著降低（P＜0.05）.水温12～25℃时,罗非鱼肠道蛋白酶和淀粉酶活性均随永温的下降而降低（在12℃时最低）,埃及尼罗肝脏脂肪酶活性20℃时最低,美国尼罗12℃时最低,美国奥利亚15℃时最低.

The effects of water temperature at 12 ℃ ,15 ℃ ,20 ℃ and 25 ℃ respectively on the digestive enzymes activity of tilapia were studied. The results showed that Egyptian strains of Nile tilapia, the activity of amylase in anterior intestion and posterior intestine, hepatic lipase and activities of lapse reduced significantly when the water temperature reduced from 25 ℃ to 20 ℃ ,15 ℃ and 12 ℃ ,and the activities of protease in anterior intestine reduced significantly at 12 ℃ compared with the temperature of 15 ℃ ,20 ℃ and 25 ℃ （P〈0.05） ,In American strains of Nile tilapia,the activities of protease in anterior intestine and activities of amylase in posterior intestine reduced significantly（P〈0.05）, and the activities of amylase,hepatic lipase and amylase of lapse in anterior intestine reduced significantly in 12 ℃. In American strains of Oreochromis aureus,the activities of amylase,hepatic lipase and activities of lapse in anterior intestine reduced significantly,and the activities of protease in anterior intestine and activities of amylase in posterior intestine reduced significantly at 12 ℃ and 15 ℃ （P〈0. 05）. When the water temperature was between 12 ℃ to 25 ℃ ,the activities of amylase and protease in intestine reduced with the decrease of the temperature with the lowest at 12 ℃. The activity of hepatic lipase was the lowest in Egyptian strains of Nile tilapia at 20 ℃ ,in American strains of Nile tilapia at 12 ℃ ,in American strains of Oreochromis aureus at 20 ℃.