Heavy metal cadmium (Cd) content in the medaka fish Oryzeas javanicus Bleeker

Abstract

The medaka oryzeas fish Oryzias javanicus Bleeker has been widely used as bioindicator animal. The present study aims to assess a lethal dose 50% (LD50) of heavy metal Cadmiun (Cd) towards test animal oryzeas fish. Fish was collected from the estuary of Jeneberang river of Makassar. Samples were acclimatized in a laboratory before being a test. Randomized Complete Design with four treatments and four replicates was applied in this study. Test fish was treated without (control) and with three different levels of Cd concentration as follows 0 mg / L; 0.008 mg / L; 0.01 mg / L and 0.03 mg/L. An observation was done during seven days experiment. Observed parameters included a change in movement, morphological abnormalities (peeled skin) as Cd content in medaka fish. Least Significance Different (LSD) method was applied to see different significant effect amongst treatments. At the end of the experiment, Cd content in test fish was determined by using an Atomic Absorption Spectrophotometer (AAS). The result indicates that medaka fish Oryzeas javanicus showed disorientation movement since day 5 at Cd concentration 0.03 mg / L and increased to the end of the test. Peeled skin happend at day seven at all three treatments (Cd 0.008; 0.01 dan 0.03 mg/L). Cd content in fish was low at concentration of 0.008 mg/L (average 1.50 mg/kg) and the highest at Cd 0.03 mg/L (average 4.19 mg/kg), respectively. Statistical analysis reveals that Cd concentration 0.03 mg/L differs from other treatments. Level of Cd accumulation in O. Javanicus Bleeker increased with an increase in metal concentration in water.