Studies on the effect of different pesticides and their combinations at 48 and 96 hour exposure on water (Moisture), protein content and calorific values in a fresh water teleostean fish, Mystus vittatus (Bloch) has been made. The treatment of Kelthane (an organochlorine), Metacid 50 (an organophosphate pesticide) and Dithane M-45 (a carbamate pesticide) increased the water content in M. vittatus, though the effect was more pronounced at 96 hr exposure as compared to 48 hrs exposure. The treatment of pesticides brought significant decrease in protein content and calorific values (k/cal/g), the maximum decrease was observed after the treatment of Metacid at 8.0 ppm after 96 hrs exposure. The details have been discussed in this paper.

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.

Studies on sublethal concentration of Carbofuran (a carbamate pesticde) and Ekalux EC 25 (an organophosphate pesticide) on changes in some haemato-biochemical parameters in an air breathing fish, Channa striatus (Bloch) were made. In control group of fishes, the values of blood glucose, plasma protein and blood urea were 68.92±1.23; 4.92±0.36 and 29.32±1.3 mg/100m1 of blood respectively. The exposure of fishes to sublethal concentrations of both the pesticides for 96 hrs caused significant increase in blood glucose and blood urea but significant decrease in plasma protein. The reason for such changes has been discussed in this paper

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.

Studies or the effect of phosalone (an organophosphate) on changes in haematological indices were made in a snake headed murrel fish, Channa gachua (Ham.). The mean values of Hb content, RBC count, Haemalocrit values, M.C.H.C. and Oxygen capacity in control group of fishes were 15.2+0.18 (g%), 2.86+0.11 (million cells/mm of blood), 23.8+1.18, 63.8 (%) and 19.0 (Vol%) respectively. Treatment of acute sub lethal dosage (8.0 ppm) of phosalone brought statistically significant decrease in most of the blood parameters except M.C.H.C. in experimental animals. The reason for such changes has been discussed in this paper.