Median Lethal Concentration (LS-50) of Lead and the Effect on Osmoregulation of the “Red Tilapia” Fish (<i>Oreochromis</i> sp.)

Abstract

The aims of this study are analyzing the score of median lethal concentration (LC50) of lead on the red tilapia fish and also test the influence of Pb exposure on osmoregulation of the red tilapia. This study consists of two steps. The first step is finding out the values of median lethal concentration (LC50) of lead on the red tilapia. The second step is finding out the influence of toxicity of lead metal exposure by giving the metal to the red tilapia maintained in the fresh water for 60 days. The lead concentration used are sub-lethal concentration 0 mg Pb/L, 1.7 mg Pb/L, 2.9 mg Pb/L, 4.9 mg Pb/L, 8.3 mg Pb/L and 14.1 mg Pb/L. The influence of lead metal exposure observed in this observation are the mortality of red tilapia fish and osmoregulation. The data of mortality are analyzed by Trimmed Spearman Karber (TSK) version 1.5 from EPA, the data of osmoregulation are analyzed by variant analysis with SPSS version 16. The result of the first step study was the values of LC50 due to the exposure of Pb metal was 13.12 mg Pb/L. The result of the second step study showed that the exposure of Pb metal also caused the disturbance of osmoregulation of red tilapia fish shown by the increase of osmotic pressure blood of red tilapia fish.