Acute toxicity of sodium cyanide and sub-lethal effects on behaviour and oxygen consumption in Catla catla and Cirrhinus mrigala Carp.

摘要

Acute toxicity of sodium cyanide and its effects on behaviour and oxygen consumption in Indian Catla catla and Cirrhinus mrigalacarp are described. Short-term acute toxicity tests were conducted by static renewal bioassay test for 96 hours with differing concentrations of sodium cyanide. The 96h LC 50 values of sodium cyanide on C. catla and C. mrigala were 0.240 mg/L and 0.458 mg/L, respectively. Fish in toxic media exhibited passive drift, active upstream movement, erratic movements, loss of balance, hyper excitability, spiral movement with sudden jerkiness, vertical movement with rapid flapping of the operculus and opened mouth and finally, settling. Respiratory activity (O 2 consumption) was affected with a decrease in metabolic rate at the end of exposures at day 7 and 14 of sub-lethal concentration in both fish species. Fish under sub-lethal concentrations were stressed but did not die.