Responses of interrenal cells of freshwater teleost, Channa punctatus (Bloch), exposed to sublethal concentrations of carbaryl and cartap

In order to record the responses of interrenal cells to sublethal exposure (30% of LC₅₀ for 96 hours) of Carbaryl (5.20 mg l⁻¹) and Cartap (0.18 mg l⁻¹), Channa punctatus were exposed for 24, 48, 72 and 96 hours under static bioassay condition. Interrenal cells of both the treated groups responded initially (by 24 hours) with the loss of staining affinity and hypertrophy of the endocrine cells. At 48 hours of exposure to the pesticides, there were significant increase in the size of interrenal cells (hypertrophy) and increased vasularization. Hyperplasia was noticed in the interrenal cells of both the treated groups at 72 hours. Though hyperplasia persisted by 96 hours, increased vascularization and marked vacuolization as well as pyknotic nuclei were frequently observed in the interrenal cells of Carbaryl- as well as Cartap-treated fish.