Liu Le-Mian, Yang Jun, Zhang Wen-Jing, Yu Zheng
Chinese Academy of Sciences, Xiamen 361021, China.
Dongwuxue Yanjiu. 2010 Aug;31(4):435-43. doi: 10.3724/SP.J.1141.2010.04435.
The morphometrical variability of six natural populations of Difflugia tuberspinifera was investigated using the statistic methods based on 374 samples from Yangtze River and Pearl River valleys. The size frequency distribution analysis indicated that D. tuberspinifera is a size-monomorphic species with normal distribution of shell height, shell diameter and aperture diameter. The size of spine length, collar height, foreside length and number of conical spines are the most variable. The correlation analysis showed that most characters are inter-correlated with P<0.05. The shell height, shell diameter, aperture diameter, spine length, collar height, rear end length, foreside length, number of aperture tooth-like structures and number of conical spines differed significantly between different populations (P<0.0001), but principal component analysis (PCA) did not clearly distinguish the six populations based on the morphometric data. However, the cluster analysis separated the six populations into two groups, the Pearl River-Yangtze River group and the Yangtze River group. Further, the populations with different shell characters can coexist within the same river valley. Thus, there is a high morphological variability or diversity within the populations of D. tuberspinifera which is related with local environmental conditions.
利用基于长江和珠江流域374个样本的统计方法，对6个自然种群的瘤刺砂壳虫（Difflugia tuberspinifera）的形态测量变异性进行了研究。大小频率分布分析表明，瘤刺砂壳虫是一种壳高、壳径和孔径呈正态分布的大小单态物种。刺长、领高、前端长度和锥形刺数量的大小变化最大。相关性分析表明，大多数性状之间存在相关性，P<0.05。不同种群之间的壳高、壳径、孔径、刺长、领高、后端长度、前端长度、孔齿状结构数量和锥形刺数量存在显著差异（P<0.0001），但主成分分析（PCA）并未根据形态测量数据清晰地区分这6个种群。然而，聚类分析将这6个种群分为两组，珠江-长江组和长江组。此外，具有不同壳特征的种群可以在同一河谷内共存。因此，瘤刺砂壳虫种群内存在较高的形态变异性或多样性，这与当地环境条件有关。
