Acute toxicity test and LC50 value of mercury on tubifex tubifex

Mercury is a heavy metal that has the highest toxicity. The toxicity of mercury will increase at the time of entry into the water. This study aims to determine the percentage of death Tubifex tubifex exposed to HgCl2 and determine LC50-48 hours of mercury in Tubifex tubifex worms. The study was divided into two stages, preliminary test and definitive toxicity acute test (LC50-48 h). Concentrations are used to test toxicities on a logarithmic scale. Observations were made every 24 hours for 48 hours. Mercury was detected by Atomic Absorption Spectrophotometer (AAS) method. The results showed that the increase in Tubifex tubifex mortality was directly proportional to the increase in HgCl2 concentration. The use of probit obtained LC50-48 h at a mercury concentration of 83.15 ± 3.89 μg / L, can be categorized into heavy metals with high toxicity. The tendency of toxicity decreases with the length of exposure time.