中国大陆钉螺螺壳形态性状聚类分析

CLUSTER ANALYSIS OF MORPHOLOGIC QUANTITATIVE TRAITS OF ONCOMELANIA HUPENSIS FROM MAIN-LAND OF CHINA

采用数量分类法对21个湖北钉螺种群的11个螺壳形态数量性状指标进行了聚类和主成分分析,以来自安徽贵池和枞阳两地钉螺种群间的欧氏距离最少为0·59,以四川丹棱和湖南华容两地钉螺种群间的欧氏距离最大为9·83,平均为4·13。从钉螺螺壳形态数量性状上可以将21个钉螺种群划分为3类:1)包括四川的广汉、蒲江、丹棱和西昌,云南大理和江苏宜兴的钉螺;2)包括湖南省洞庭湖区的君山、南县和华容,江西省鄱阳湖区的南昌、星子和都昌,湖北阳新、汉川和蔡甸的钉螺;3)包括江苏的江宁和丹徒,安徽的枞阳、贵池和铜陵,湖北江陵的钉螺。

The pomatiopsid medical importance as various snail genus Oncomelania is of taxa transmit the human blood fluke Schistosoma japonicum, and lung fluke species of the genus Paragonimus in China, Japan, the Philippines, and Indonesia. Oncomelania hupensis is the only intermediate host of S.japonicum, and is mainly distributed along the Yangtze River and down to the basin of the Yangtze River including 404 counties/cities in 12 provinces, The taxonomy of Oncomelania hupensis has been confused over the years in part of one character （shell sculpture） and two trait-states （shell smooth/shell ribbed）. External morphological quantitative traits of Oncomelania species were analyzed by using cluster analysis and principal component analysis method in the present paper. A total of 1260 （60 individual per snail population ） specimens of 21 snail populations were used and 11 shell morphological traits were measured for quantitative taxonomic analysis. The average values of 11 quantitative traits were computed respectively for 21 snail populations and a snail population was used to analyze as an operational taxonomic unit （OUT）, These average values were standardized by subtracting the mean of variable and the difference divided by the standard deviation, The Euclidean distances between different snail populations were computed for cluster analysis, and a correlation matrix was computed among the variables for the principal components analysis, The Euclidean distance between snail populations from Guichi and Zongyang in Anhui Province was the least （0.59） and between snail populations from Danling, Sichuan Province and Huarong, Hunan Province was the most （9.83）, The average Euclidean distance between different snail populations was 4.13, According to 11 morphological quantitative traits, the result of the cluster analysis and principle component analysis showed that three species-groups could be divided： 1 ） Sichuan-Guanghan, Sichuan-Pujiang, Sichuan- Danling, Yunnan-Dali and Jiangsu-Yixing; 2） Hunan-Junshan, Hunan-Nanxian, Hunan- Huarong, Jiangxi- Nanchang, Jiangxi-Xingzi, Jiangxi-Duchang, Hubei-Yangxin, Hubei-Hanchuan and Hubei-Caidian; 3） Jiangsu-Jiangning, Jiangsu-Dantu, Anhui-Zongyang, Anhui-Guichi, Anhui-Tongling and Hubei-Jiangling, O, h, hupensis （Liu et al. , 1981） might continue to subdivide.