敌百虫对水丝蚓的毒害

采用急性毒性方法测定了被不同浓度敌百虫毒害的水丝蚓(Limnodilus hoffineisteri)半致死浓度(LC50),利用测定酶活性方法检测了水丝蚓超氧化物歧化酶(SOD)的变化及中毒后水丝蚓喂饲的强壮水螅(Hydra robusta)SOD的改变。(1)敌百虫对水丝蚓48 h LC50为3.29 mg/L。敌百虫对水丝蚓SOD活性影响显著(P<0.05):在低浓度1~4 mg/L时,SOD活性呈上升趋势,但随浓度增加至5 mg/L,SOD活性开始下降。(2)用1~8 mg/L中毒后的水丝蚓依次喂饲水螅,SOD活性呈上升趋势。实验结果表明,敌百虫作为重要的杀虫剂或作为防治鱼病的药物,对水丝蚓造成胁迫,并在一定浓度范围内直接或间接地影响以其为食的动物的生存,以至危害生命。     

Changes of C-reactive protein levels in rainbow trout (Oncorhynchus mykiss) sera after exposure to anti-ectoparasitic chemicals used in aquaculture

Changes of serum C-reactive protein (CRP) levels in rainbow trout (Oncorhynchus mykiss) were studied after exposure to formalin, metriphonate or potassium permanganate, which are used in aquaculture as anti-ectoparasitic chemicals. The CRP level in normal trout sera is 88+/-5 microg ml(-1) according to sandwich enzyme-linked immunosorbent assay. CRP levels increased to a maximum at six or nine days after exposure to formalin for 3.5 h at 300 ppm or 9.5 h at 30 ppm, respectively; these levels are 4.3 and 18 times higher than normal. At 18 days after treatment, the CRP level had decreased to significantly below the normal level. After exposure to metriphonate (0.4 ppm for 30 min), the CRP level increased significantly to a maximum at three days after exposure (9.9 times higher than normal), then decreased to below normal. With exposure to potassium permanganate at 40 ppm for 45 min, fish showed significantly lower CRP levels than the normal level at 14 days after exposure. Fish reared at a water temperature of 16.5-19.5 degrees C showed significantly higher CRP levels than those reared at 13 degrees C. Measurement of CRP levels in trout serum can be used as a bioindicator of the health condition of the fish.