1347-0159

AA11577672

16504

査読無

We elucidated the behavioral changes of freshwater snail (Semisulcospira libertina) exposed to heavy metals for biological monitoring of water quality. Freshwater snails were exposed to copper sulfate (CuS$O_4$; 0,0.1,1 or 10mg/L), or cadmium chloride (CdC$l_2$; 0,0.01,0.1,1 or 10mg/L) for 4 days. The behavior of snails were observed at the end of exposure test and classified with five behaviors (movement, M; adhesion and cessation of muscular activity, AC; detachment and muscular activity, DM; detachment and cessation of muscular activity, DC; withdrawal of the body into the shell, W). As a result, exposure of CuS$O_4$ and CdC$l_2$ induced significant change of behaviors in snails, respectively (p<0.05). In the 0.1 CuS$O_4$-mg/L treatment group, all snails showed W behavior after the exposure. And 7 out of 8 snails showed W behavior in the 1mg/L group. Additionally, in the 10mg/L group, W and DC behavior were observed from 5 and 3 snails, respectively. However, no death was observed in all CuS$O_4$ treatments, and 6 out of 8 snails in the control showed M behavior. In CdC$l_2$ exposure, M behavior was observed in the 0.01mg/L group, and 5 out of 8 snails showed M behavior in the 0.1mg/L treatment. On the other hand, M behavior was observed from only 1 out of 8 snails, in the 1 mg/L treatment, and 4 out of 8 snails showed W behavior. In addition, all test organism showed W behavior in the 10mg/L group. However, the death was not observed in all CdC$l2_$ treatments. Additionally, we compared the observed effect concentration determined from this study with the recorded concentrations of Cu and Cd in the environment. And we concluded that the behavior of freshwater snails could be affected by high recorded Cu concentration.