Chlorine killed fish are safe for human consumption. Anhydrous ammonia when applied at the rate of 20–25 ppm kills the predatory and weed fishes. Besides, it also controls the aquatic weeds and later acts as nitrogenous fertilizer. Toxicity of ammonia lasts for 4–6 weeks.
Answers & Comments
Explanation:
Derris Powder is used to kill predatory fishes .
C is the right answer .
Verified answer
Answer:
derris powder is used to kill predotory fish
Explanation:
Chlorine killed fish are safe for human consumption. Anhydrous ammonia when applied at the rate of 20–25 ppm kills the predatory and weed fishes. Besides, it also controls the aquatic weeds and later acts as nitrogenous fertilizer. Toxicity of ammonia lasts for 4–6 weeks.