苯酚、Cu(上标 2+)、亚硝酸盐和总氨氮对中华鲟稚鱼的急性毒性

Acute toxicities of phenol, Cu(superscript 2+) nitrite and total ammonia to juvenile Chinese sturgeon Acipenser sinensis fingerlings were determined in static bioassays. The juveniles with (2.36 ± 0.10) cm in total length and average 0.07 g in body weight were 8-12 day old just before the yolk would be completely exhausted. It was found that the 24, 48, 72 h and 96 h median lethal concentration (LC50) values (95% confidence interval) of the phenol to the juveniles were 97 (87-109), 83 (73-95), 75 (69-83)mg/L and 71 (64-80)mg/L, respectively. The 24, 48, 72 h and 96 h LC50 values (95% confidence interval) of Cu(superscript 2+) to the juveniles were 0.31(0.29-0.34), 0.20 (0.15-0.27), 0.09 (0.08-0.12)mg/L and 0.07 (0.06-0.10)mg/L, respectively. The 24, 48, 72 h and 96 h LC50 values (95% confidence interval) of nitrite-N to the juveniles were 7.05 (6.22-8.03), 4.07 (1.51-7.88), 3.10 (2.07-4.34)mg/L and 2.57 (2.31-2.85) mg/L, respectively. The 24, 48, 72 h and 96h LC50 values (95% confidence interval) of unionized ammonia-N to the juveniles were 0.67 (0.64-1.07), 0.52 (0.44-0.67), 0.43 (0.40-0.54)mg/L and 0.39 (0.30-0.45)mg/L, respectively. The juveniles had higher heart beating rates (119±10 beat/min, n=10) in 126 mg/L phenol than those in the control group (106±5 beat/min, n=10) (P＜0.05). There was no significant difference in heart rates in 0.4 mg/L Cu(superscript 2+) and in the control group (P＞0.05). The juveniles had significantly higher heart beating rates in 20.30 mg/L nitrite-N (112±4 beat/min, n=10) and 29.20 mg/L total ammonia-N (112±7 beat/min, n=10) than in the control group (P＜0.05).