Alterations in serum electrolyte levels after dimethoate exposure and recovery in the freshwater air-breathing catfish, Heteropneustes fossilis (Bloch)

Abstract

Dimethoate, a moderately toxic insecticide, has a wide range of agricultural and domestic applications. Like other organophosphates, dimethoate has anticholinesterase activity. Fish are non-target organisms, inadvertently exposed to pesticides and their metabolic products. The present study includes short-term (96 h) and long-term (36 d) effects of dimethoate exposure on some serum electrolytes Ca²⁺, Mg²⁺, and Pi in the freshwater air-breathing catfish Heteropneustes fossilis. The concentration of dimethoate for short-term exposure was 2.24 mg L⁻¹ (75% of 96 h LC₅₀) and for long-term exposure 0.75 mg L⁻¹ (25% of 96 h LC₅₀). The study includes the recovery pattern in serum electrolytes after placing the fish in pesticide-free water. Fish show hypocalcemia, hypermagnesemia, and hyperphosphatemia after short-term and long-term exposure to dimethoate. When placed in pesticide-free water, these electrolytes exhibit recovery towards normalization, indicating significant (p < 0.05) recovery.

Keywords:

• dimethoate
• Heteropneustes fossilis
• serum electrolytes (Ca²⁺, Mg²⁺, and Pi)
• recovery

Acknowledgments

Authors are thankful to the Principal, Kamla Nehru Institute of Physical and Social Sciences, Sultanpur, for providing required research facilities.