Pakistan's most of the land is less productive or no productivity at all due to erosion and salinity of the soil, which can be utilized to develop fisheries. The project, "Survival, growth and body composition of Cyprinus carpio under different salinity regimes" was undertaken in two phases. In the first phase susceptibility of Cyprinus carpio at four salinity levels in triplicate within 0-10 g L-1NaCl for 96 h in each aquarium was checked after one week acclamation at 0 g L-1, 2 g L-1 and 4 g L-1 NaCl. LC50 values varied from 7.67 to 10.65 g L-1 after 96 h for C. carpio. Percentage mortality of the fish and important water quality parameters after every 12 h were observed for a period of 96-h. Probit analysis showed that 96-h LC50 values ranged from 7.67 to 10.65 g L-1 . During experimental period aquaria water temperature ranged from 29.6 to 33.7 °C, pH values fluctuated between 7.8 and 9.7, Electrical conductivity values ranged from 2.40 to 20.13 dSm-1 and Dissolved oxygen ranged between 2.23 and 10 mg L-1. Sub-lethal salt concentration i.e. 0 g L-1 to 3 g L-1 NaCl upto 40 days showed that growth of C. carpio decreased with the increase of water salinity levels and ceased at 4 g L-1 salinity and increase in salinity have negatively affected hematological parameters.
Keywords: Common carp; Haematology; LC50; Physico-chemical parameters; Salinity; Toxicity.