The Biotoxicity Of Triazophos, Sodium Pentachlorophenate, Zinc And Cadmium To Daphnia Carinata

The serious aquatic pollution restricts the sustainable development of economy and is dangerous to the human healthy and survival. In order to protect water resources free from pollution, it is necessary to monitor aquatic pollution in real time in the management of water resource. Usually, there are two ways to monitor aquatic environments: physics/chemistry and biology. They have both advantages and disadvantages in the procuration of monitoring information and need to be cooperated and replenished mutually in order to provide accurate and correct information. The biomonitor methods are under developing and still have some limits such as poor accuracy, complex operation and difficult application, it is urgent to set up some accurate, quick and reliable methods for biomonitoring in present aquatic environment protection.Daphnia (Cladocero: crustacea), an important animal of the diet for many fish, is widespread in the world and has a critical role in aquatic ecology chains. It is a new technology under investigation to detect the toxicants by using phototactic behaviour of Daphnia as an index, which provides a prospect application in biomonitoring. But such research is just in consummation and the information in theories and practices is limited. So, a lot of fundamental research work need to be done, including the selection of Daphnia as biomonitor sensitive to toxicants but less to environment changes, the exploitation of relationship between the phototactic behavior of Daphnia and pollutants such as heavy metal, pesticide and their mixtures, and the comprehension of the effect of environmental conditions such as fish kairomones on the phototactic behavior of Daphnia. All the research above is very important to establish standard methods for detecting the toxicants in water.At present, the pollutions of heavy metals, pesticides and their mixtures are the main environmental problems in fresh water. But more researches were carried out on the pollution of single heavy metal and pesticide more than their mixtures. It is thus necessary to clarify the effects of heavy metals and pesticides on the phototactic behavior of Daphnia and to realize the biological and environmental effects in the condition of toxicant coexistence. They are important presuppositions that need to be solved before eliminating water pollution.In the present experiments, Daphnia carinata clone Dc₄, which was selected from Sanxia areas and breaded by self-copulation, was used to study the acute toxicity of triazophos, sodium pentachlorophenate (PCP) and heavy metals (Zn and Cd). The median lethal concentrations,...