摘要
目的 研究护堤隔离沟改造钉螺孳生环境 ,消灭钉螺的效果。方法 以有隔离沟洲滩为试验组 ,无隔离沟洲滩为对照组。在两组外洲钉螺分布高程设置网箱 ,人工投活螺 ,比较钉螺产卵数量、幼螺生长发育状况、钉螺自然死亡率和感染螺密度 ,测量隔离沟区域洲土含水量 ,调查隔离沟沉积层各年间钙化螺密度。结果 试验组外洲无钉螺孳生。当东洞庭湖水位退至 2 5 m左右 ,对照组钉螺分布带洲土平均含水量 38.1% ,高于试验组 2 8.3% ;人工投活螺后对照组产卵数高于试验组 ;试验组幼螺出现率显著低于对照组和室内模拟现场。春季网箱外湖水中捞幼螺数 ,试验组显著低于对照组 ;网箱内秋季查螺 ,试验组钉螺自然死亡率 (77.92 % )显著高于对照组 (4 1.6 7% ) ;隔离沟淤积层内钙化螺筛洗 ,上层显著低于中层 ,中层又低于底层。莫河铺外洲对照组网箱内活螺密度、感染螺密度显著高于试验组。对照组外洲高杆植被生长茂盛 ,试验组外洲无高杆植被。结论 洞庭湖退水期间 ,植被被淹死 ,气温较高 ,隔离沟能迅速沥干洲土积水 ,改变了洲滩潮湿的环境 。
Objective To evaluate the eff ec t of environmental modification in Oncomelania s nail habitats through the application of isolated canals to reduce moisture in l ake marshlands. Methods The marshland with isol ated canals was acted as the experiment group, and that without isolated canals as control one. The boxes with living snails were placed in snail habitat areas in the lake marshland, and the amount of oviposition, the growth and development of young snails, nature death rate of snails and density of infected snails wer e observed. The moisture within isolated canal was measured, and the density of calcified snails was investigated. Results No s nails were found in natural environment of the experimental group. As the water level receded to 25 meters, the moisture in the control group(38.1%) was more than that in the experimental group(28.3%), and there was a significant diff erence. After putting the living snails into the set boxes, less ova and young s nails were found in the experimental group compared with those in the control gr oup. In spring, the number of snails was less, and the death rate(41.67%)was higher in the experimental group than those in the control group(77.92%). Mor e calcified snails were found in the bottom layer than those in the medium and u pper layers within the isolated canal. More living snails and infected snails we re found in the boxes of the control group than those of the experimental group in the lake marshland of Mohepu. Tall vegetation was rich in lake marshland of t he control group, while none was found in the marshland of the experimental grou p. Conclusion During the receding period, the is olated canal can quickly spread the water and reduce the moisture, and so the en viron- [HT5”SS]ment is unsuitable for snail survival. [HT5”SS][
出处
《中国血吸虫病防治杂志》
CAS
CSCD
2004年第5期338-342,F002,共6页
Chinese Journal of Schistosomiasis Control
基金
湖南省水利厅资助 ( ID:2 0 0 2 0 5 15 )
关键词
隔离沟
改造
钉螺
控制
Isolated canal
Modi fication
Oncomelania snail
Control
