温度、pH和盐度对后背鲈鲤幼鱼存活的影响

EFFECTS OF TEMPERATURE, pH AND SALINITY ON THE SURVIVAL OF JUVENILE PERCOCYPRIS PINGI RETRODORSLIS

为了研究后背鲈鲤(Percocypris pingi retrodorslis)对温度、pH和盐度的耐受性,以后背鲈鲤幼鱼为实验材料,采用单因子静态急性毒性实验法对其温度、pH和盐度耐受能力进行研究。实验结果表明,后背鲈鲤幼鱼对温度的耐受范围为0—32℃,高温、低温的半致死温度分别为32℃和1℃,最佳生长温度为8—27℃;96h内,最佳生长pH为5.0—9.0,pH高于9.5或者低于4.7时,幼鱼出现死亡,在24、48、72、96h里,不同碱度对幼鱼存活率的影响呈现显著性差异(P<0.05),而不同酸度对幼鱼存活率的影响差异性不显著(P>0.05),24、48、72、96h酸度半致死浓度(LC50)相应pH分别为3.90、3.96、4.15、4.40,碱度半致死浓度相应的pH分别为11.20、11.10、10.98、10.89。96h内,当盐浓度超过7.50 g/L时,幼鱼开始死亡,不同盐浓度对幼鱼的存活率的影响呈现显著性差异(P<0.05),盐度对实验鱼的12、24、48、72、96h的半致死浓度分别为10.30、9.25、9.00、8.85、8.82 g/L,2个级别的安全浓度(SC)分别为0.882 g/L、2.557 g/L。后背鲈鲤已被列入珍稀濒危物种,研究为今后后背鲈鲤的人工养殖和跨地域养殖打下理论基础。

To study the tolerance of Percocypris pingi retrodorslis to temperature, pH, and salinity, the juvenile Percocypris pingi retrodorslis were used as experimental objects. A single factor static acute toxicity test was used to study their tolerance to temperature, pH and salinity. The experimental results showed that their tolerance on temperature ranged from 0 to 32℃, and the lethal high and low temperature was 32℃ and 1℃, respectively. The optimum growth temperature was between 8 and 27℃. In addition, the optimum growth pH was 5.0—9.0. However, the juvenile fish began to die when pH was higher than 9.5 or lower than 4.7（within 96 h after treatment）. The effects of different alkalinity on the survival of juvenile fish have significant difference（P〈0.05）, after the treatment for 24 h, 48 h, 72 h and 96 h,but there was no significant difference effects on the survival at different acidity level（P〉0.05）. The LC50 of acidity for the juvenile fish was 3.90, 3.96, 4.15 and 4.40 after treated for 24 h, 48 h, 72 h and 96 h, respectively. The LC50 of alkalinity was 11.20, 11.10, 10.98 and 10.89 after the treatment of 24 h, 48 h, 72 h and 96 h, respectively. The juvenile fish began to die when salinity was higher than 7.5, and the effects of different salinity on the survival of juvenile fish were significantly different（P〈0.05）. The LC50 of salinity for juvenile fish was 10.30, 9.25, 9, 8.85 and 8.82 g/L at 12 h, 24 h,48 h, 72 h and 96 h after treatment, respectively, and two safe concentration（SC） levels were 0.89 g/L and 2.385 g/L. The Percocypris pingi retrodorslis has been listed as endangered species, and our data will provide a theoretical foundation for the artificial breeding and trans regional breeding of Percocypris pingi retrodorslis.