中国湖北钉螺(腹足纲:圆口螺科)分类现状

SYSTEMATIC STATUS OF ONCOMELANIA HUPENSIS (GASTROPODA: POMATIOPSIDAE)THROUGHOUT CHINA

本文对采自中国境内不同水域、不问螺壳类型的14个螺群的同工酶数据进行了遗传分化研究,探讨中国湖北钉螺的分类现状。结果表明,中国钉螺存在重要的遗传分化及与避传分化相关的可分辨的类型。对此进行研究后还发现了县城交叉传播和亚种间可能存在3个例外杂合螺群的依据;此外。螺群遗传分化类型与地理分布、螺壳刻纹和形态特征相一致。以此为基础,湖北钉螺(Oncomelania hupensis)再分成3个独立的亚种:滇川亚种(O.h.robertsoni)、福建亚种(O.h.tangi)和湖北亚种(O.h.hupensis)。

Measures of population divergence for Oncomelania can be derived from shell characters, anatomical characters,or molecular genetics distances. This study explores genetic divergence based on allozyme data involving 14 populations widespread throughout China,are in divergent drainage systems,and have different shell phenotypes. The authors examined 25 loci. Nei’s genetic distance ranged from 0. 007 to 0. 453.While there is no correlation of increasing genetic distance with geographic distance,the authors found coherent discernable patterns to the genetic differentiation. Careful examination of these patterns provided evidence for one case of cross-country transport of snails,and for the existence of three exceptional populations that appear to indicate that hybridizations between subspecies may have occurred. Excluding these four populations,patterns of genetic differentiation were in general correlated with geographic distribution and shell sculptural and shape characters. These patterns thus served as the bases for subdivision of O. hupensis into three discrete subspecies :O. h. robertsoni ,O. h. tangi and O. h. hupensis.