DOI: 10.36347/sajb.2017.v05i09.017

Pages: 682-687

Heavy metals are considered as the most important pollutants, since they are present throughout the ecosystem and are detectable in critical amounts. Heavy metals, such as lead (Pb), copper (Cu), arsenic (As), zinc (Zn), chromium (Cr), nickel (Ni), cobalt (Co), cadmium (Cd), mercury (Hg), manganese (Mn) are the pollutants which affect aquatic environment and fish. The aim of the present study was to determine and compare the acute toxicity of two different heavy metals viz. Lead and Cobalt on zebrafish, Danio rerio. The mortality rate of zebrafish was monitored under laboratory conditions for the time period of 24, 48, 72 and 96-h. Data obtained from the toxicity test were evaluated using by the Stat plus® computer program. The 96-h LC50 of lead is 21.63mg/L and for cobalt 69.83mg/L, it was found that lead is more toxic to zebrafish as compared to cobalt. Zebrafish can be used as bio-indicator to assess the heavy metals pollution in aquatic environment.