中国近海棱梭群体形态学和耳石形态学研究

Morphology and otolith morphology of Chelon affinis populations in the coastal waters of China

为研究棱梭不同地理群体间的形态差异,使用多元统计分析方法对采集自金门、厦门、虎门、湛江、北海和防城港6个地点邻近海域的棱梭群体样本的形态和矢耳石形态两方面进行比较研究。对棱梭样本的形态研究结合传统形态学和地标形态学开展,对矢耳石的形态研究则将传统耳石形态分析法和椭圆傅里叶分析法相结合,形态和耳石形态数据的分析结果相似。主成分分析结果表明从28个棱梭形态量度指标提取的前8个主成分累积贡献率为65.868%,从85个耳石形态指标提取的前23个主成分的累积贡献率为79.290%,根据临界值85.000%可以推断这6个棱梭群体间形态和耳石形态上的差异不能够单独依靠少数指标来判断;聚类分析的结果总体显示出群体间差异与地理距离等因素相关联的分布规律;在判别分析中形态学量度指标的综合判别正确率为75.9%,而耳石形态学指标的综合判别正确率略低,为69.3%;对棱梭形态量度指标的单因子方差分析显示湛江棱梭群体与其他群体在形态上存在显著差异的量度指标较少。栖息地环境、饵料组成和海流等可能是导致形态学差异和耳石形态差异形成的主要因素。另一方面,理化因子的相似性和群体间的交流会减弱群体间形态和耳石形态的差异。

In order to study morphometry differences in Chelon affinis populations,both variations of morphological character and otolith morphometry were compared by multivariate statistical analysis based on the samples collected from six populations in the coastal waters of Jinmen,Xiamen,Humen,Zhanjiang,Beihai and Fangchenggang. The morphology study was carried out used both traditional morphology and landmark morphology and otolith morphology was studied by the combination of traditional otolith morphology analysis and elliptic Fourier analysis. Similar results were obtained by the study of morphology and otolith morphology. The results of principal component analysis showed that the first 8 principal components extracted from 28 morphological characters explained 65. 868% of the total variance and that 79. 290% of the total variance could be explained by the first 23 principal components extracted from 85 otolith morphological indices. Therefore,it could be concluded that the difference of morphology and otolith morphology among C. affinis populations could not be presented by only a few indices according to the critical value(85. 000%). The correlations among geographic distribution and morphological and otolith morphological variations were presented in cluster analysis. The results of the discriminant analysis showed that the average classification ratio based on morphological characters was 75. 9% compared with lower value 69. 3% based on otolith indices. It was found that with one-way ANOVA analysis on the morphological measurements the Zhanjiang population had the least indices different significantly from the other populations. On the one hand,the differences in diet composition,habitats and currents may lead to the existent variations of morphology and otolith morphology.On the other hand,the similarity of physicochemical factors and communications among groups would reduce their differences.