1.Heilongjiang River Fisheries Research Institute,Chinese Academy of Fishery Sciences,Harbin 150070,China;2.College of Fishery and Life Science,Shanghai Ocean University,Shanghai 201306,China;3.College of Marine Sciences,Ningbo University,Ningbo 315211,China; 4.Dalainuori Fish Farm,Chifeng 025350,China
Abstract: The acute toxicity of salinity and alkalinity to 3 month old crucian carp Carassius auratus with body length of 4.16 cm±0.47 cm in Dali Lake was studied at various concentrations of salinity prepared by NaCl,alkalinity from(NaHCO3)and saline-alkaline mixture by one-way and two-way of salt or/and alkaline tests.Based on the values of LC50for salinity and alkalinity at different time,the marking additive index(AI)was adopted to evaluate the effects of joint toxicity on the crucian carp.The results showed that the values of LC50of salinity were found to be 11.57 at 24 h,11.14 at 48 h,10.89 at 72 h,and 10.61 at 96 h at alkalinity of 0.44 mmol/L and pH 7.0± 0.5,with the safe salinity of 3.10.Under the conditions of salinity 1.9-4.3 and pH 8.5±0.5,the values of LC50of carbonate-alkalinity were 71.93 mmol/L at 24 h,67.80 mmol/L at 48 h,65.80 mmol/L at 72 h and 63.42 mmol/L at 96 h with the safe alkalinity of 18.07 mmol/L.The toxic effects were antagonism in 96 h,but declined and tended to be additive.The findings provided theoretic basis for the culture and enhancement of crucian carp in saline-alkaline inland such as Dali Lake in future.
2013, Vol. 28 
