Tolerance level and metabolic response of <i>Clarias gariepinus</i> fingerlings to potassium permanganate toxicity.

Abstract

Potassium permanganate is one of the widely used chemicals in aquaculture, its usage if not properly controlled may stress the cultured fish. This study examined the metabolic responses of C. gariepinus fingerlings to stress due to potassium permanganate toxicity. Fingerlings of C. gariepinus of the same parental stock were placed randomly in six plastic tanks; ten fingerlings were placed in each of the tanks. Each tank was exposed to 1.5mg/l of potassium permanganate. The exposure time served as treatments and it was varied as follows: 0 (control), 6, 24, 48, 72 and 96 hours. The blood samples were collected at each time interval as listed above. These samples were analyzed for heamatological and biochemical parameters. The Red Blood Cell (RBC) value decreased significantly (p< 0.05) from 3.45 ± 0.69 106l recorded in fish exposed to 0 hour of potassium permanganate to 2.30 ± 0.47 106l in 24 hour of exposure, this latter gradually increased in 48 hours of exposure to 3.91 ± 0.21 106l at 96 hour of exposure. The plasma glucose level in the C. gariepinus exposed to potassium permanganate increase significantly (p< 0.05) to 98.20 ± 2.09mM under 6 hour of exposure from 94.15 ± 1.87mM, this was followed by rapid but significant reduction to 56.00 ± 2.34mM at 96 hour of exposure. Potassium permanganate is relatively nontoxic to cultured fish species, however at certain concentration level, this study has shown that it may affect the physiological state of the fish. It is therefore recommended that the fish farmer should have clear understanding of the mechanism of using potassium permanganate so as to minimize the possible toxic effect of potassium permanganate. 

Keywords: Toxicity, metablolic response, Potassium permanganate, Clarias gariepinus