Study On Behavioral Responses Of The Aquatic Organisms Under The Joint Stress Of Environmental Pollutants

At present, the water pollution caused water ecological imbalance. Under a certain environmental stresses, the biological behavior of aquatic organisms is the response to adapt to the changes of the external environment and internal physiology. So when the external environment changes, the adaptability of aquatic organisms to the environment demonstrate are behavioral changes firstly, and through behavioral regulatory mechanisms to maintain stable internal environment. If the unusual behavioral changes of aquatic organisms can be observed,the change of one or a number of factors of the external environment may be beyond the normal extent of the adaptability of aquatic organisms, and thus, we can infer the changes of water quality.As the complexity of water pollution, aquatic organisms are not only affected by a certain kind of pollutants, but also by the combined effects of several pollutants. Therefore, it is necessary to focus on research of behavioral responses to stress of aquatic organisms under the combined effects of multiple pollutants.1. from the results of the combined effects, the stepwise behavioral responses of the Japanese medaka under the joint stress of environmental pollutants is consistent with the Daphnia's stepwise stress model exposed in pollution. The behavior strength always experienced a decline after the first increase, then restore and decrease. The iterative process accord the environment stepwise stress model.2. In the joint exposure, the stepwise behavioral responses of the Japanese medaka not only affected by the concentration of environmental pollutants, but also affected by the exposure time, and the evident difference of the behavioral responses time was not detected, so there are no obvious synergistic or inhibitory between two environmental pollutants.3. The behavior strength and the concentration of the pesticide exposed showed inverted "U"-type relationship, within 48 hours of the average behavior strength gradually increased with the concentration of the pesticides, until reach a certain degree, with the increase of the concentration, their behavior strength decreased gradually until death. There is powerful relationship between the time exposed until dramatic changes of the behavior strength and the relative concentration of organophosphorus pesticides based on LC50-48.4. The behavioral responses of the Japanese medaka under the exposure of heavy metal is obviously slow. As the toxicity of cumulative effects,environmental stress resulting from heavy metals is less than the same TU concentrations, and the behavior strength has correlativity with the exposed time, in addition to the high concentration, its strength always experienced a decline after the first increase, then restore and decrease. The iterative process accord the environment stepwise stress model. In the adjustment process of the biological behavior,environmental stress threshold is probable the decisive role of biological behavior changes.