Efficacy of nine laboratory chemicals against the free living developmental stages of Lernaea cyprinacea Hemaprasanth, Sridhar N., Raghunath M.R. Peninsular Aquaculture Division, Central Institute of Freshwater Aquaculture, Hessarghatta Lake, Bangalore-560 089, India Abstract Efficacy of varying concentrations of potassium permanganate, copper sulphate, potassium dichromate, acriflavin, picric acid, ammonium chloride, sodium chloride, potassium iodide and formaldehyde against the nauplius and copepodid stages of Lernaea cyprinacea were studied. Formaldehyde, picric acid and ammonium chloride are capable of killing the free living developmental stages of Lernaea at the lowest concentrations studied. Formalin and picric acid at 0.025% concentration were able to kill the nauplius stages within 21.00 and 16.00 min and copepodid I stages within 3.25 and 1.50 min of exposure, respectively. Ammonium chloride at 0.05% concentration was effective in killing the copepodid I stages within 9 min of exposure. However, it was observed that copper sulphate, acriflavin, potassium iodide, potassium permanganate and potassium dichromate were effective against the developmental stages at a much higher concentration reported to be toxic to the fish host. The possibility of using ammonium chloride which is commonly used as a fertilizer as a potential chemical in killing the free living stages of Lernaea cyprinacea, thereby disrupting the developmental cycle of the parasite is discussed. Top Keywords Efficacy, Chemicals, Lernaea, Nauplius, Copepodid. Top |