Abstract: In order to explore the effects of cadmium on metallothionein (MT) content of Pirata subpiraticus and its growth and development, offsprings of P. subpiraticus female adults collected from five different habitats were fed on Drosophila melanogaster reared under 5 different Cd²⁺ concentrations in the laboratory. After sexually matured, then the MT content in body, growth rate and survival rate of these female spiders were tested. The results showed that excessive cadmium in food can be transferred by food chain and accumulated in P. subpiraticus and the accumulation level increased with cadmium concentration increasing. The induced expression level of MT was positively related with Cd²⁺ concentration (P<0.05). When Cd²⁺ concentration was less than 20 μg/g, the expression level of MT in P. subpiraticus from polluted sites （S1, S2, S3 and S4） was significantly higher than that from the control site S5 (P<0.05). On the contrary， when Cd²⁺ concentration was higher than 20 μg/g, however, the expression levels of MT in P. subpiraticus from all sites had no significant difference. The survival and growth rates of P. subpiraticus decreased with increasing Cd²⁺ concentration. It is so concluded that MT plays an important role in tolerance mechanism in P. subpiraticus, and MT increases significantly in a concentration-dependent manner with heavy metals.

Key words: Pirata subpiraticus, heavy metal pollution, cadmium, metallothionein, survival rate, growth and development