基于标记重捕回收技术的湖沼钉螺异地生存和繁殖研究

Survival and reproduction of imported Oncomelania snails from lakes and marshes by the capture-mark-recapture method

目的采用标记重捕技术研究野生湖沼型钉螺在水网地区持续生存和繁殖情况,为研究钉螺异地迁徙的生存可能提供科学依据。方法2010年11月25日将使用不褪色油性标记物标记后的安徽省池州市贵池区产野生钉螺(雌雄比例为1∶1)50、100、200、400、800和1600只随机投放于任屯村血吸虫防治纪念馆6个钉螺实验池中,连续观察3828 d,2021年5月19日采用双层箩筛水洗法将实验池中钉螺筛出进行分类计数。利用Excel 2007和SPSS 10.0软件对钉螺的连续监测数据进行绘图,同时计算重捕数和重捕率。采用Kruskal-Wallis H检验比较不同投放量间的重捕率差异,对数线性回归法比较不同投螺量条件下子代螺数量差异。结果共投放3150只钉螺,从6个实验池内捕获钉螺1167只,经水浸法和镜检法确定均为空壳钉螺,未发现活螺。其中有标记的实验钉螺366只,重捕率为11.62%,子代钉螺(含幼螺)694只,残螺107只。不同投放量的重捕率差异有统计学意义(χ^(2)=75.743,P<0.001),不同投放量与子代钉螺重捕数量不存在线性回归关系[y=211.84lgx-403.68,F=6.543,P=0.063]。结论湖沼型钉螺在异地水网地区可以生存繁殖,但不具备持续的繁殖生存能力。钉螺监测工作应重点关注邻近地区同亚型钉螺的扩散而非远距离不同亚型钉螺的传播。

Objective To investigate the survival and reproduction of wild imported Oncomelania snails from lakes in water network regions by the capture-mark-recapture method,and to provide a scientific basis for the survival possibility of the long-distance migration of Oncomelania snails.Methods On November 25 of 2010,50,100,200,400,800,and1600 of wild Oncomelania snails(at a male/female ratio of 1∶1)from Guichi district of Chizhou city in Anhui,China,were randomly put into 6 ponds after marked by non-fading markers in Rentun Schistosomiasis Memorial Hall and were observed for 3828 consecutive days.On May 19 of 2021,the double-layer-mesh was used to screen and wash out the snails from the ponds for classifying and counting.Excel 2007 and SPSS 10.0 softwares were used to perform a statistical analysis of continuous monitoring data and calculate the number of recapture and recapture rate.The Kruskal-Wallis H test was used to compare the difference in recovery rate between different doses of snails,and the logarithmic linear regression analysis was used to investigate the correlation between the dose of snails and the number of second-birth snails.Results A total of 1167 snails were captured from the 6 ponds,all of which were found empty by water immersion and microscopy,and no living snail was observed.Among these snails,366 were marked experimental snails,with a recapture rate of 11.62%,and there were 694 second-birth snails(including young snails)and 107 incomplete snails.The Kruskal-Wallis H test showed a statistical difference in recovery rate between different doses of snails(χ^(2)=75.743,P<0.001).No linear regression relationship was observed between the dose of snails and the number of secondbirth snails recycled[y=211.84 lgx-403.68,F=6.543,P=0.063].Conclusion Oncomelania snails from lakes can survive and reproduce in water network regions,but they do not have the ability for continuous survival and reproduction.The surveillance of Oncomelania snails should focus on the spread of Oncomelania snails of the same subtype in neighborhood,rather than the spread of Oncomelania snails of different subtypes from a great distance.