Physiological and histopathological responses of carp, Cyprinus carpio to sublethal levels of lead

Physiological and histopathological changes in carp, Cyprinus carpio after exposure to sublethal levels of lead for 96 hr. have been investigated. The median lethal concentration of lead was 2.940 mg/L. The descending order of lead accumulation after exposure of carp to 0.48, 1.68, 2.52mg/L lead for 96hr. was the kidney, gills, brain, liver and flesh. An increase in plasma glucose levels and average hemoglobin content of individual red cells were observed in this study, while plasma aspartate aminotransferase decreased. Plasma sodium ions showed slight but significant changes. Histological studies revealed extensive damage had occurred in the gills, liver and kidneys. On the other hand, fish exposed to 105.0, 210.0mg/L lead exhibited a significant disturbances in fish swimming performance and electrocardiograms

Bioaccumulation of lead and its effects on growth performance and some haematological aspects of carp, Cyprinus carpio

The aim of this study is to assess lead bioaccumulation and its effects on growth performance and some haematological aspects of carp, Cyprinus carpio to elucidate the mode and site of lead toxicity. Fish exposed to sublethal concentrations of lead [21.0, 42.0 micro g/L] for 49 days exhibited a significant changes in growth performance as measured by total weight gain, feed utilization and body composition. Lead has been also showed to cause anaemia in fish with changes in the activity of plasma aspartate aminotransferase and creatinine. Changes in plasma glucose levels and sodium ions were insignificant. On the other hand, lead was selectively accumulated in tissues and organs of carp. It was greatly accumulated in the spleen followed by the brain, kidney, liver, gills and flesh. The accumulation of lead by tissues induced a disturbance in the deposition and distribution of calcium and iron elements