湖北钉螺在非适宜地东平湖生存繁殖的纵向观察

目的在南水北调条件下,观察人工北移至非适宜地区山东省东平湖区湖北钉螺生存繁殖的能力。方法近年,在东平湖区的湖心岛以螺笼放养钉螺,定量观察其生存繁殖情况。结果亲代钉螺可以在东平湖越冬生存,存活率为60.51%(118/195);经过2个冬季24个月放养,繁殖产生了子2代钉螺228只,其螺口数量较亲代钉螺数量增长了14.00%;经过3个冬季36个月放养,钉螺繁殖产生了子3代钉螺86只,其数量较亲代钉螺减少了57.00%,与子2代钉螺数量比较减少了62.28%;经过4个冬季48个月放养,钉螺存活率为0。结论南水北调东线南端长江取水口地区的湖北钉螺在血吸虫病非流行区山东省东平湖区可以繁殖到子3代,生存繁殖的时间不超过4个冬季、48个月,呈现逐年消亡趋势。报道了在中国大陆北纬35 055/地区,人工北移到此地的钉螺在湖滩铁丝笼内放养状态下生存繁殖的纵向观察结果。

Longitudinal observation on the reproduction and survivability of the north-migrating Oncomelania hupensis in Dongping Lake,Shandong Province

Objective Under the condition of South-to-North Water Transfer project,the viability and fertility of oncomelania hupensis migrating to unsuitable areas in the north part by the anthropic factor were observed in Dongping Lake Area in Shandong Province.Methods In recent years,in the mid-lake island of Dongping Lake Area,oncomelania hupensis were breeding in cages,and their viability and fertility were quantitatively observed.Results Parental generation could live through the winter in Dongping Lake,and the survival rate was 60.51％ (118/195);After 24-month stocking,(two winters)oncomelania hupensis reproduced 228 snails of filial generation Ⅱ,whose number increased by 14.00％,as compared with those of parental generation.After 36 month-stocking (three winters),oncomelania hupensis reproduced 86 snails of filial generation Ⅲ,whose number reduced by 57.00％,as compared with those of parental generation,and decreased by 62.28％,as compared with those of filial generation Ⅱ;After 48 month-stocking (four winters),the survival rate of oncomelania hupensis was 0.Conclusion Oncomelania hupensis of Hubei in the southern part of the Eastern Route of South-to-North Water Transfer Project could reproduce to the third filial generation in the non-endemic area of schistosomiasis in Dongping Lake,Shandong Province.The survival and breeding time was no more than 48 months (four winters),and oncomelania hupensis appeared to die out year by year.This research reported the longitudinal observation of the viability and fertility of oncomelania hupensis in northern latitude 35 055 area of Chinese mainland,in which oncomelania hupensis were moved to the north part by the anthropic factor,and bred in cages in lakeshore.