山东微山湖区子代钉螺壳形变异的研究

目的 目的 探讨钉螺被人为迁移至南水北调山东受水区后其子代钉螺壳形变化特点。方法 方法 取微山湖区独山岛饲 养的钉螺， 以亲代钉螺107只为对照组， 同时测量子1代螺115只、 子2代螺107只， 收集螺体壳长 （L）、 壳宽 （W）、 壳口宽 （AW）、 壳口长 （AL）、 唇脊厚度 （LIT） 等数据， 并计数体螺旋纵肋数。结果 结果 子代钉螺LIT明显减少， 并随子代数增加呈递减 状态， 三代螺两两比较， LIT差异有统计学意义 （P < 0.01）； 同时， 子代螺L和AL降低， W和AW增加， 壳口长与宽之积增加， 体螺旋纵肋数增加。结论 结论 微山湖子代钉螺的螺体变小、 螺壳变薄， 提示微山湖区非完全适宜钉螺孳生， 但是种群可以生 存多年。

Study on shell shape changes of filial generation Oncomelania hupensis snails inWeishan Lake region,Shandong Province

Objective To explore the shape change characteristics of Oncomelania hupensis snail shell after the snails being passively migrated into Shandong intake area of the South-to-North Water Diversion Project. Methods The snails raised on the Dushan island in Weishan Lake region were captured, and 115 the first filial generation snails and 107 the second filial generation ones were selected. The length and width of shells and apertures, and the labial ridge thickness of those snails were measured, the longitudinal rib number of snail spiral was counted, and 107 parental snails were chosen as controls. Results The labial ridge thickness of the filial generation snail was significantly reduced with the increase of algebras, and the labial ridge thickness among the 3 generations had a significant difference （P 〈 0.01 ）. Both the length of snail shell and the width of snail apertures were de creased, while the width of snail shell, the length of snail apertures, the multiplication product of snail aperture＇ s length and width and the longitudinal rib number of snail spiral were all increased. Conclusion The body size of Oncomelania snails in Weishan Lake region becomes smaller, and their shells become thinner, which indicates that the environment of the lake region is not suitable for snail breeding, and the snails have natural decay tendency with the extension of time.