异地江滩钉螺迁入新长滩生存繁殖观察

Dynamic changes of survival and propagation of snails moved from marshland beach to new settlement along Yangtze river

目的观察异地江滩钉螺迁入仪征新涨滩后的生存、繁殖和螺口消长动态变化,为江滩现场螺情监测和防治提供科学依据。方法采集鄂、赣、皖和仪征本地江滩钉螺,在室内作适应性饲养数天并作雌雄配对后放入现场滩地特制的螺笼内饲养,定期观察其钉螺的生存、繁殖和螺口消长变化。结果鄂、赣、皖3地江滩钉螺迁入新涨滩地后的越冬死亡率为15.96%～21.74%,年生存率在21.33%～30.38%之间;三地钉螺与本地对照生殖腺发育正常,呈现明显的季节和周期变化特征;产卵高峰期在3～5月间,其中鄂、赣、皖三地钉螺比本地对照的产卵高峰有所推迟(约15d左右),而产卵数、螺卵孵化率和年增殖倍数与本地对照钉螺间均无显著差异(χ2=0.11820、0.62540和1.38699,P均>0.05);同时在长江汛期实验滩地水域打捞漂浮物检获钉螺6次(68只)。结论鄂、赣、皖三地钉螺迁移至仪征新涨滩地后均能生存和繁殖并受着外来钉螺随漂浮物侵袭滩地的威胁,但在短期内不会构成滩地螺情的迅速蔓延。提示今后加强新涨滩地的螺情监测,防止外来钉螺侵袭并对现有密度较高的有螺滩地,强化灭螺措施确保灭螺质量依然是关键,以巩固血防成果。

Objective To observe the survival and progation of snails moved from marshland beach new Yizheng settlement.Methods Snails were collected from the provinces of Hubei,Jiangxi,Anhui and local marshland snails and kept indoors for several days and put into a special screw-site beach feeding cage after the male snails were matched with female ones.Then the survival and propagation and the changes of number of snails were regularly observed.Results The mortality rates of snails from Hubei,Jiangxi,Anhui after move into the new marshland were 15.96%～21.74%,the annual survival;rates were 21.33%～30.38%.The spawning peak of the snails was from March to May.The spraining peak of snails from Hubei,Jiangxi and Anhui was delayed about 15 days compared with local control.But the number of eggs,ege hatching rate and annual multiplication were the same compared to the local ones（χ2=0.11820,0.62540 and 1.39628,P0.05）.Conclusion The snails moved from Hubei,Jiangxi,Anhui to new settlement（Yizheng） could survive,propagate and face the rist of snails invading from outside along with the floating subject.The monitoring of sanils and prevention of invading of snails from outside are the key measures to consolidate the results of schistosimiasis control.