| Heavy metal pollution has already been a global issue, greatly threating human health and biodiversity. With the rapid urbanization and economic development, the heavy metal pollution is more extensive and intensive around China than before. The heavy metal pollution sources are of automobiles, industrial wastes, pesticides and fertilizers and atmospheric deposition, etc. It is well known that heavy metals can’t be chemically degraded in the environment, but they can pass through food chain and food webs, harmful to organisms. Currently, the heavy metals in the environmental and organisms are conventionally detected by physical-chemical methods through sophisticated equipments to get the real their amount. However, chronic effects caused by long term explosion to the ow-dose heavy metals are uneasily detectable through the physical and chemical means. Moreover, accurately reflect the combined effects of heavy metals pollution on organisms and ecosystems. Therefore, we can detect the distribution of heavy metals in different parts of organisms and the responsive effects of organisms to heavy metal sin the process of development, production, physiological and biochemical process.This paper mainly concerned the effects of cadmium on the growth and development of, predation and the cadmium accumulation in the Pirata piratoid.es, feeding on cadmium contaminated drosophila, Our purpose is to ask whether Pirata piratoides is a potential biological indicator of heavy metal pollution in paddy field.The treated group (15 individuals per treat, three repeats) of Pirata piratoides, were fed on cadmium contaminated drosophila (41.7±7.2μg/g), and the control group (15 individuals per treat, three repeats) were fed on non-cadmium contaminated drosophila (4.67±0.47μg/g). When the female spiderlings of control group grew up, they were raised by certain concentration heavy metal instead of water(10mg/L、50mg/L'100mg/L). Then the predatory rates in five continuous times after application were observed and compared. All the drosophila and spider were reared under the condition of 25℃. RH 80% and 14 L:10 D. Our results showed that the development duration (49.87±0.65 days) of treated group was significantly longer than control group (42.17±0.82 days). In addition, other than the fifth instar, the development duration of third, fourth and sixth of treated group were also longer than those of control group. The body weights of female adults of the treated group (0.0130±0.0007g) were significantly decreased than those of control group (0.0157±0.0014g). The cadmium in the treated spider bodies (52.23±4.13μg/g) was 14 times higher than that in controlled spiders (3.77±1.26μg/g). The predation rates of control group (9.68±0.08 prey) and 10mg/L treated group (9.86±0.13 prey) were significantly increased than those of 50mg/L treated group (7.30±0.29 prey) and 100mg/L treated group (6.86±0.33 prey). The predation rates of control group (9.68±0.08 prey) were significantly decreased than those of 10mg/L treated group (9.86±0.13 prey). The biomagnification factor was approximately 1.2. Our resulted suggested that cadmium could be passed through the food chain and accumulated in Pirata piratoides, resulted in hindering its development and production. Pirata piratoides is a potential bio-indicator of the impact of cadmium on the biodiversity in paddy field. |
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