The adaptation of leech(Haemadipsa hainana)to temperature and soil humidity
海南山蛭对土壤湿度和气温的适应

Haemadipsa hainana is exposed to a soil humidity gradient in the laboratory. The result show that the soil water content of H. hainana habit is ranging from 15.1% to 16.77%.The field investigation in the rubber plantation show that its suitable habit is with soil water content from 16.54% to 17.66%.In the tropical rainforest its habit soil water content is ranging from 19.2% to 25.75%. Observation in door shows that non of H.hainana is active at temperature 8℃ to 9℃, leech begin to active at 10℃，all leech are active at 15℃, active number increases with increasing temperature within the observed temperature rang 79.15% of leech crawls towards 30℃ to 35℃.Adaptation of leech to temperature and soil humidity is discussed.