钉螺在巢湖生存繁殖的现场研究

目的了解钉螺能否在巢湖生存繁殖.方法选择巢湖湖区的马尾河口和巢湖闸两处为实验区,巢湖东岸高林山区为对照区,投放无为县江外滩的肋壳钉螺和巢湖东岸高林山区的光壳钉螺,观察钉螺在放养不同时间后的生存繁殖情况.结果1年后,实验区和对照区均有相当数量存活的肋壳钉螺和光壳钉螺成螺;研究期间在实验区和对照区均检获了一定数量的光壳钉螺和肋壳钉螺幼螺;产卵期间实验区和对照区肋壳钉螺存活率差异无显著性(P＞0.05),而光壳钉螺存活率差异具有显著性(P＜0.05);产卵期间无论是光壳钉螺还是肋壳钉螺,各实验区雌螺卵巢中所含螺卵数与同一月份对照区同类雌螺卵巢中所含螺卵数的差异均无显著性(P均＞0.05).结论肋壳钉螺、光壳钉螺均能够在巢湖生存繁殖,但光壳钉螺在巢湖的生存状况不及其在高林山区的生存状况理想.

Field study on survival and reproduction of Oncomelania snails in Lake Chao

Objective To understand whether Oncomelania snails can survive and reproduce in Lake Chao. Methods Two areas, the estuary of the Mawei River and the place nearby the floodgate of Lake Chao which both belong to the regions of Lake Chao, were selected as experimental spots, and the mountain area of Gaolin close to the east bank of Lake Chao was selected as the control spot. The snails with ribbon shells from the beach of the Yangtze River nearby Wuwei County and the snails with smooth shells from the mountain area of Gaolin were put into each spot, and the survival abilities and the reproductive capacities of the snails in different time were observed. Results One year later, there were considerable survival mature snails with ribbon/smooth shells in each spot. During the period of the study, many immature snails with ribbon/smooth shells were found both in the experimental spots and in the control spot. During the seasons of egg-laying, there was no significant difference between the experimental spots and the control spot in the aspect of the survival rate of the snails with ribbon shells (P>0.05), but there was a significant difference between the experimental spots and the control spot in the aspect of the survival rate of the snails with smooth shells (P<0.05). During the period of egg-laying, whether the sanils with ribbon shells or the snails with smooth shells, there were no significant differences between the experimental spots and the control spot in the aspect of eggs in the ovaries of female snails in the same month. Conclusion Both snails with ribbon shells and snails with smooth shells can survive and reproduce in Lake Chao, but snails with smooth shells can survive better in the mountain area of Gaolin than that in Lake Chao.