The present work is an endeavour to study the toxicity and behavioural responses of the fish Channa punctatus (Bloch) at different concentrations of a weedicide (Aquathol or Endothal) during static acute bioassays. The TLm or LC50 values were computed to be 3.162, 2.405, 2.290 and 1.550 mg/I at 31.0±1.00C respectively for 24, 48, 72 and 96 hrs exposures of aquathol. The safe concentration value was computed to be 0.418 mg/I at this temperature. The behavioural response of Channa punctatus (Bloch) was grossly depenent on the concentration and length of exposure.
In the present work an attempt has been made to find out the variations in biochemical composition and calorific values in an air breathing fish Channa punctatus (Bloch) under chronic exposure of different pesticides and their combinations besides assessing whether or not the obtained data also can be used as an indicator for assessing water quality and its management.