Journal of Environmental Biology

Acute and chronic toxicity of copper on aquatic insect

Chironomus ramosus from Assam, India

Author Details

T.N. Majumdar

Department of Zoology, Haflong Government College, Haflong - 788 819, India

A. Gupta

(Corresponding author)

Department of Ecology and Environmental Science, Assam Central University, Silchar - 788 011, India

e-mail: abhik.eco@gmail.com

Publication Data

Paper received:

06 July 2010

Revised received:

05 January 2011

Accepted:

05 February 2011

Abstract

Acute toxicity of copper (Cu) on Chironomus ramosus was determined by exposing third-instar larvae to graded concentrations of copper sulphate (CuSO₄. 5H₂O). Median lethal concentrations (LC₅₀) of Cu as CuSO₄ at 24, 48, 72 and 96 hr were determined as 3280, 1073.33, 780, and 183 mg l^-1, respectively. For determining the effects of chronic toxicity, small first-instar larvae were individually exposed to sublethal concentrations of copper sulphate (1.0-18.0 mg l^-1) for a period of 21 days. Discoloration and thinning of body were detected at 1 mg l^-1 and ventilation movements, pupation and adult emergence were significantly affected at 1.8 mg l^-1. At 10 mg l^-1 CuSO₄ concentration, growth and tube-building activities of the larva were significantly different from the control.

Key words

Acute and Chronic toxicity, Median lethal concentrations, Chironomus ramosus, Copper sulphate ?

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