Histological alterations of a combination of Chlorpyrifos and Cypermethrin (Nurocombi) insecticide in the fresh water crab, Paratelphusa jacquemontii (Rathbun)

Chlorpyrifos (CPF) and Cypermethrin (CPM) are toxic and subject to long-term in vivo accumulation in different aquatic species throughout the world. The purpose of the present study was to examine the combined CPF/CPM (Nurocombi) exposure on histology in various tissues of Paratelphusa jacquemontii. The crabs were exposed to combined CPF/CPM concentrations of 0.0187ppm and 0.0374ppm (sub lethal) for 28days with parallel untreated control. The experimental gill tissue exhibited epithelial lifting, edema, necrosis, fusion of secondary lamellae and hemorrhage. The deceased hepatopancreas revealed infiltration, formation of large lumen and disappearance of haemocytes. The pathologic symptoms like atrophy, necrosis, wavy appearance, accumulation of granular material in between muscle fibers, fragmentation, loss of muscle structure, appearance of basophilic deposits were displayed in the muscle tissue. The vas deferens showed remarkable epithelial vacuolar degeneration, irregular appearance of spermatophore matrix associated with reduction in the number of spermatophores and dehiscence of most of the spermatophores. It is concluded that histological biomarkers provide reliable and discriminatory data to augment pesticide pollution and therefore, long-term monitoring is necessary to assess the eco-health of the mangrove system.