翘嘴红鲌雌雄个体的形态差异分析

为研究翘嘴红鲌(Eryghroculter ilishaeformis)主要形态指标和雌雄个体的形态差异,2016年3月采集了67尾翘嘴红鲌,对其全长/体长、体高/体长、体宽/体长、尾柄长/体长、尾柄高/体长、眼间距/头长、头高/头长、头宽/头长、吻长/头长和丰满度10项标准化比例性状进行主成分分析、R-聚类分析和逐步判别分析,并建立了雌雄判别方程式。主成分分析和R-聚类分析结果显示,翘嘴红鲌主要形态指标可分为肥瘦程度特征、躯干部特征、尾部特征和头部特征4个方面。散布图结果显示雌雄个体在尾部形态上存在差异,同判别分析结果一致。通过逐步判别法从67尾翘嘴红鲌的10项标准化性状中筛选出体高/体长、体宽/体长、尾柄高/体长和丰满度4个比例性状,建立性别判别方程,对群体识别正确率达91.0%。经T检验,除体高/体长外,其他3个比例性状在两性群体间均存在显著或极显著差异,表明雌性相较于雄性体型较宽、较丰满,但尾柄较矮。上述差异性状及雌雄判别方程式可为翘嘴红鲌性别的鉴定提供方法和理论依据。

Analysis of morphological indexes and discrimination of male and female Eryghroculter ilishaeformis

To study the main morphological indexes of Eryghroculter ilishaeformis and morphological variations between male and female, a total of 12 quantitative characters of 67 individuals collected in March 2016 were measured. 10 charac-teristics( total length/body length, body height/body length, body breadth/body length, caudal peduncle length/body length, caudal peduncle height/body length, eye distance/head length, head height/head length, head breadth/head length, snout length/head length and fatness) were normalized and further used for Principal Component Analysis, R-cluster Analysis and Stepwise Discriminant Analysis. Principal Component Analysis and R-cluster Analysis indicated that the morphological index system of E. ilishaeformis could be classified into the level of obesity, the body feature, the caudal peduncle and head feature. The distribution of principal component 1 and 3 showed that E. ilishaeformis could be classified by caudal peduncle feature, which was in keeping with Stepwise Discriminant Analysis. Four normalized traits involving body height/body length, body breadth/body length, caudal peduncle height/body length and fatness were screened out by Stepwise Discriminant Analysis based on the contribution of variables to the discriminant function. On the basis of the four normalized traits, sex discriminant equations were established and the accuracy rate for identifying 67 samples was 91. 0%. Further, the T-text results of four normalized traits between male and female were significantly different ( P<0. 05 or P<0. 01), except for the feature of body hepth/body length. Therefore, we concluded that the female E. ilishaeformis were su-perior to male in the respect of body breadth and fatness but having smaller caudal peduncle height than that of male. In conclusion, the differential characters and the discriminant equations for male and female could be a simple and efficient method for sex identification of E. ilishaeformis.