Study On Population Ecology Of China Toad(Bufo Gargarizans) In Shanghai Suburbs

The China Toad (Bufo Gargarizans), usually called "laihama", falls into the category of Amphibian Salientia Bufonidae. It is a species specially protected in Shanghai and it is in the List of Nationally-protected Land Wild Animals of Benefit, Financial Value and Scientific Research Value. Bufo Gargarizans plays a significant ecological role in the protection of crops and the maintenance of ecological balance.The population of Bufo Gargarizans has greatly decreased due to various factors such as habitat destruction, environmental pollution, disease, ultraviolet radiation, overexploitation, etc. Therefore, it is of great significance to carry out an ecological research about Bufo Gargarizans population in Shanghai suburbs and to investigate the features and degree of being threatened so as to serve as a theoretical basis for the exploitation and protection of Bufo gargarizans.This research is carried out by means of sample line and studied the respective Bufo gargarizans populations in five Shanghai suburbs. In this research, the changes of population density are analyzed. At the meantime, relations between body length, body weight, lens weight and age, breeding ecology of Bufo gargarizans are taken into consideration on the basis of laboratory dissection. In addition, a social survey is conducted to study the exploitation status of Bufo gargarizans in Shanghai. Following is a clustering analysis with lens weight/body length as indexes about the division of age groups of various populations.The Bufo Gargarizans in Shanghai suburbs finish their hibernation from the end of February to the beginning of March. After that, the adult ones gradually come to waters and enter into breeding period (from March to the beginning of April). During the breeding period, they choose static waters for couplings and laying eggs. Their eggs, black and almost round, are arrayed interlaced and parallel. In the late May, they leave waters and switch to lives on lands. They stay in their caves and come out for preys (mainly insects) from evening to early morning. In the end of October, they move to waters and then begin their hibernation when the temperature is below 10℃ and finish the hibernation at the end of next February.The population peak of Bufo gargarizans is supposed to be the time when...