Piscicidal potential of mesocarp of neem plant (Azadirachta indica L.) fruit on hybrid, "Heteroclarias".

The piscicidal potential of water-extract mesocarp of Azadirachta indica (L) was studied in static bioassay experiment with continuous aeration to determine its acute toxicity The mortality rate and opercular ventilation under laboratory conditions over 96 hr exposure were monitored. The 96 hrLC50 was 81.28 mgl(-1) while the threshold value was 21.13 mgl(-1). The fish exhibited respiratory distress (such as gasping air), loss of appetite, loss of balance and erratic swimming prior to mortality.

Productivity potentials and nutritional values of semi-arid zone earthworm (Hyperiodrilus euryaulos; Clausen, 1967) cultured in organic wastes as fish meal supplement.

In the present study 60 Adult Earthworms (H. euryaulos) of weight and length range 1.7-3.0 g (mean-2.34 +/- 0.91 g) and 13.0-28.0 cm (mean-21.5 +/- 5.8 cm), respectively were cultured for 12 weeks. The productivity potential and nutrient composition of earthworm (H. euryaulos) cultured in two rearing substrata (Cellulose Substrate (Control)--Coded Hs1 and Dry Neem and leaves and soil Substrate--Coded Hs2) were assessed using six wooden boxes stocked in triplicates at the rate of 92.7 g earthworms per box. The higher total final weight, weekly weight gain, relative growth rate, specific growth rate and survival of 400.6 g kg(-1) of substrate, 25.7 g/week/substrate, 332.5, 0.76/day and 99.0% while the lower of 367.5 g kg(-1) of substrate, 22.9 g/week, 296.4, 0.71/day and 98.0% were recorded in earthworm cultured in cellulose substrate and the soil substrate respectively. The proximate analyses, mineral compositions and amino acids indices were comparable to those of conventional fish meal. Based on the results of this study, the utilization of cellulose substrate is recommended for the culture of earthworm and the inclusion of the earthworm meal is guarantee as a reliable and nutritional dependable fish meal supplement.