摘要
采用96 h静水停食实验法,以体质量为(19.70±1.98)g的大口黑鲈幼鱼为研究对象,研究了氨氮的96 h半致死浓度(LC50)并依据96 h LC50设置低(19 mg·L^-1)、中(28.5 mg·L^-1)、高(38 mg·L^-1)和对照4个浓度组进行胁迫,在6、12、24、48、72和96 h时分别检测其鳃、肝、肠、肾和脑组织中的酸性磷酸酶(ACP)、过氧化氢酶(CAT)活性及丙二醛(MDA)的含量。结果表明:ACP、CAT(除肠部)活性及MDA含量在96 h实验时间段内总体上均呈现先升高后逐渐降低的变化趋势,均与对照组有显著变化(P<0.05)。大口黑鲈幼鱼的96 h LC50为63.34 mg·L^-1,但当氨氮浓度28.5 mg·L^-1时经96 h胁迫其部分组织细胞功能已受到损伤,其鳃ACP活性和鳃、肠CAT活性能够准确反映所受损伤的程度,可作为评价养殖水体中氨氮毒性的标志物。
Ammonia nitrogen(N)is a major source of water aquaculture and a cause of fish diseases.The acute toxicity experiment of ammonia-N to juvenile Macropterus salmoides in weight(19.70±1.98)g was carried out in static water without feeding at water temperature 21.0℃,pH 7.9,and dissolved oxygen 8.0 mg·L^-1.This study was first exposed to total ammonia-N for 96 h to obtain the median lethal concentration(LC50)at 96 h.According to the data,we set up a control group and three ammonia-N treatments of which the concentration were low group,middle group and high group.In each group the subjects were treated for a series of periods(0,6,12,24,48,72 and 96 h).The acid phosphatase(ACP)and catalase(CAT)activity and the malondialdehyde(MDA)content of the gill,liver,intestine,kidney and brain were measured.After 96 h treatment with ammonia-N,the ACP and CAT(except the intestine)activity and the MDA content showed a trend of increasing first and then decreasing with prolonged exposure,which was significantly different from the control group(P<0.05).Although the 96 h LC50 of total ammonia-N on juvenile M.salmoides was 63.34 mg·L^-1,when the ammonia-N concentration was 28.5 mg·L^-1,the cell function in some tissues was damaged after 96 h treatment.The CAT activity in the gill and intestine and the ACP activity in the gill can accurately reflect the degree of oxidative damage,and can be used as a marker to evaluate the toxicity of ammonia-N in aquaculture water.
作者
郑洪武
杨斯琪
孙颖
朱爱意
ZHENG Hong-wu;YANG Si-qi;SUN Ying(National Engineering Research Center of Marine Facilities Aquaculture,Zhoushan 316022,China)
出处
《浙江海洋大学学报（自然科学版）》
CAS
北大核心
2020年第1期27-33,共7页
Journal of Zhejiang Ocean University：Natural Science
基金
国家海洋公益性项目(201505025)。
