M. SHUHAIMI-OTHMAN, Y. NADZIFAH, R. NUR-AMALINA AND A.K. AHMAD
Abstract
The susceptibility of freshwater organisms to metal has been determined in a laboratory. Acute toxicity tests were performed on eight different freshwater species, namely Macrobrachium lanchesteri (prawn), Poecilia reticulata and Rasbora sumatrana (fish), Melanoides tuberculata (snail), Stenocypris major (ostracod), Chironomus javanus (midge larvae), Nais elinguis (annelid) and Duttaphrynus melanostictus (tadpole). The purpose of this study was to determine the susceptibilities of species to metals based on 96-h LC50 values for Cu, Cd, Al, Mn, Fe, Pb, Ni and Zn. In order to compare the susceptibilities of species to metals, a relative tolerance index was calculated. Based on the index, annelid N. elinguis was the most susceptible species and the snail M. tuberculata was the most resistant. Lowest 96-h LC50 values of Mn (0.36 mg/L), Fe (0.12 mg/L) and Ni (0.64 mg/L) was to N. elinguis; Cd (0.007 mg/L) and Pb (0.035 mg/L) to M. lanchesteri; Cu (0.006 mg/L) and Zn (0.46 mg/L) to R. sumatrana; and Al (1.43 mg/L) to C. javanus. Results also indicated that among the eight organisms tested there were no extreme resistance organisms.