山丘区钉螺大小特征与水分依赖性

本文研究了山丘区钉螺壳体长宽鲜重体积,以及疫区壳体长宽与区域降水温度的关系。仁寿县钉螺鲜重0.0162 g(浮动在0.0065 g～0.0219 g之间),体积4.5894 mm3(3.12 mm3～5.6 mm3),长度5.156 mm(3.6 mm～6mm),宽度为2.668 mm(2.2 mm～3 mm)。分析表明,长度5 mm～6 mm为主体,宽度2.5 mm～3 mm为主体,钉螺宽度随着长度作缓慢而显著的增加;鲜重与群体的长度、宽度、体积无关。潮湿稻田生境钉螺长度明显最大,而干燥与湿润生境中次之,但宽度、体积、鲜重差异不明。疫区不同区域钉螺长度、宽度与降水量显著相关,而与温度无关,温度降水量比值与钉螺长度、宽度关系密切,表明钉螺大小有水分依赖性。在疫区内,可能水温匹配性共同塑造了钉螺的大小。

Snail Size Characteristics and its Moisture Dependency in Hilly Mountainous Areas

In this paper, studies are made of the snail length, width, volume and weight in hilly mountain- ous areas and the relationship between the snail length or width and precipitation and temperature. The weight of the snail was 0. 0162 g （ varying from 0. 0065 g to 0. 0219 g）, its volume was 4. 5894 mm3 （3.12 mm3 -5.6 mm3） ,its length was 5. 156 mm（3.6 mm -6 mm） ,and its width was 2. 668 mm（2. 2 mm - 3 mm） in Renshou County. Analysis results have indicated that snails of 5 mm- 6 mm length and 2. 5 mm - 3 mm width account for a main proportion, their width will have a slow and significant increase along with the increase of their length. And no relations are found between weight and population length, width and volume. The snail length is the largest in humid rice land, and takes the second place in relative dry and humid habitats but no differences are found in the snail width, volume and weight. The length and width of snail have a significant relationship with precipitation, and no relationship is found with temperature. And yet their length and width have an obvious relationship with the ratio of temperature and precipitation in epidemic areas, implying the moistre dependency of the snail size. Possibly, the moisture and its adaptability to temperature can commonly shape the snail size in epidemic areas.