4种鲌的星耳石形态度量学比较

Comparative studies on multivariate morphometrics of asteriscus of four culters

对来自9个采样点的鲌属(Culter)翘嘴鲌(C.alburnus)、蒙古鲌(C.mongolicus)、达氏鲌(C.dabryi)和近红鲌属(Ancherythroculter)黑尾近红鲌(A.nigrocauda)共810尾个体星耳石的8个特征值进行形态度量,运用Statistica软件作鲌类鱼体生长与耳石生长的回归分析、形态特征值及6个形态因子和6个形态指数的多变量统计分析。结果显示:(1)4种鲌耳石形态存在极显著差异。(2)幂函数回归方程相对于直线回归方程能更好地表述鲌体生长及耳石生长关系;鲌类体质量与耳石质量、体长与耳石直径的回归方程近于线性回归关系,体质量与耳石直径、与体长回归方程幂值分别近于3.5、3,而耳石质量与耳石直径回归方程幂值近于2。耳石质量增长速度与体质量增长速度相近,但耳石质量相对耳石长度的增长速度较体质量相对体长或耳石长度的增长速度要慢。(3)鲌耳石形态度量特征值判别函数分析判别正确率达71.11%,对识别影响较大的特征值为耳石宽、耳石面积、耳石长、基叶长等;通过4种鲌耳石形态因子和形态指数的主成分分析,对识别影响较大的形态因子为F2、F1、F6、F5和形态指数为形态系数、充实度、椭圆率等。(4)采用鲌类群体耳石形态度量特征值判别分析和聚类分析,均能较好地区分翘嘴鲌3个长江群体(太湖、鄱阳湖、丹江口水库)与漓江群体、蒙古鲌鄱阳湖5个群体(新妙湖、南北港、青岚湖、庐山西海、章江),其群体聚类距离与群体间的地理距离相关联。本研究结果说明,星耳石形态度量分析能为鲌类物种或群体间关联性分析提供依据。

Eight characteristic values of asteriscus from 810 individuals in four culters species,including Culter alburnus,C.mongolicus,C.dabryi and Ancherythroculter nigrocauda,from 9 sampling points,were measured,and the regression analysis between culter’s body growth and otolith growth,and multivariate statistical analysis of morphological characters,six shape factors and six shape indices were analyzed using Statistica software.The results showed that:(1)There were significant differences of the asteriscus morphology among the four culters.(2)Power function regression equation could better describe the relationship between the culter’s body growth and otolith growth than linear regression equation.The regression equations between culter’s body quality and otolith quality,and between standard length and otolith diameter were approximate to linear regression relation,with the exponential value of regression equation between body quality and otolith diameter and standard length being 3.5 and 3,and between otolith quality and otolith diameter being 2.The growth rate of otolith mass was similar to that of body mass,but the growth rate of otolith mass relative to otolith length was slower than that of body mass relative to standard length or otolith length.(3)Discriminant function analysis of culter’s morphological characters had an accuracy of 71.11%,and the characteristic values that had great influence on the identification were OW,OA,OL and BL,etc.Through principal component analysis of the shape factors and shape indices,F2,F1,F6,F5 and CF,CR,EL,etc.had a greater influence on the recognition of shape.(4)Through otolith morphological characters discriminant analysis and cluster analysis among culter populations,it could be better distinguished from three Changjiang groups of C.alburnus(from Taihu Lake,Poyang Lake,and Danjiangkou Reservoir),the Lijiang group,and five Poyang Lake groups of C.mongolicus(from Xinmiao Lake,Nanbeigang Lake,Qilang Lake,Lushan West Sea Reservoir,and Zhangjiang River),with the group clustering distance associated with geographic distance among the populations.In short,asteriscus shape analysis in this study provides a basis for correlation analysis among culter species or populations.