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The snail’s specie, Oncomelania quadrasi, is found abundantly in fresh water fish ponds of Punjab. It is an intermediate carrier / host of various digenetic trematode parasites which causes many serious fish diseases in aquaculture ponds. The purpose of this study was targeted for controlling these snails in aquatic environments through chemical control strategies using copper sulfate as an eradicant. Mainly three trials were conducted to determine the effectiveness of copper sulfate against this snail sp. in laboratory aquaria conditions. Trial I involved the copper sulfate treatment sprayed directly for reductions of snails present on the upper moist layer of soil. Trial II was demonstrated for reductions of the snail densities buried under the depth of 8-16 inch layer of soil. Trial III was managed to study the copper sulfate toxicity on the survival of snails and Labeo rohita present together in the same aquatic media. The study indicated that copper sulfate was effective for eradication of the snails in all conditions whether present on the wet edges / moist soil surfaces, buried in the soils or present in the aquatic environment with fish, however, with varying degrees and intensities.

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A 10-week feeding experiment was conducted to evaluate the effects of feeding level, energy and protein maintenance requirement of rainbow trout, Oncorhynchus mykiss, fingerling (5.65±0.45cm; 1.42±0.25g) by feeding casein-gelatin based purified diet (45% CP; 3.67 kcal g^-1 GE) at six feeding levels from 2 to 7% of BW/day in two equal meals, at 0800 and 1700 h, in triplicate, with 20 fish per trough equipped with continuous water flow-through system water (60L volume). Maximum live weight gain, best feed conversion ratio (FCR), best specific growth rate (SGR) and highest protein efficiency ratio (PER) were reported in fish fed 4-5% BW day^-1. However, quadratic regression analysis for weight gain, FCR, PER, protein retention efficiency and energy retention efficiency data indicated the break-points occurred at 5.33, 4.50, 4.48, 4.63 and 4.74% BW day^-1, respectively. Body composition also produced significant (p<0.05) differences with respect to each feeding level, maximum protein, lowest moisture and intermediate fat contents were reported at 4-5% feeding levels. Protein and energy retention values also produced significant (p<0.05) differences among each feeding level with maximum values were reported at 5% feeding level. Based on the results, it is recommended that feeding in the range of 4.6 to 5.3% BW day^-1, corresponding to 2.07-2.39g protein and 16.88-19.45 kcal energy g100g^-1 of the diet day^-1 is optimum for the growth and efficient feed utilization of rainbow trout, while 2-3% feeding levels (0.90-1.35g protein and 7.34-11.01 kcal energy) suggests that these amounts approximate the maintenance requirement of fish.