中国沿海龙头鱼群体多变量形态特征的比较

为查明我国沿海不同地理群体龙头鱼（Harpadon nehereus）外部形态差异，采用传统形态学测定和几何框架度量法对8个龙头鱼群体共计199尾个体的29个可量性状进行了多元统计分析。主成分分析提取了排序前7位的主成分，获得累计贡献率达71.481%。主成分散点图显示舟山和潮州群体与其他群体差异较大，其中第1主成分反映了臀鳍大小及腹鳍至臀鳍间的躯体斜向大小差异；主成分2受到双眼间距离和口裂大小的影响。单因素方差分析显示仅特征值口裂/头长（MCL/HL）、腹鳍起点至脂鳍起点/体长（D₃-D₈/BL）、臀鳍起点至背鳍起点/体长（D₅-D₆/BL）和臀鳍基部末端至脂鳍基部末端/体长（D₇-D₁₀/BL）在各群体间未检测到显著性差异（P<0.05）。聚类树显示舟山群体聚在最外层，与其余群体差异较大，其次为海口和青岛群体。用逐步回归分析法选取9个作用最大的特征值建立判别公式，样本被判入青岛群体的判别准确率为100%，综合辨别率为66.9%。研究结果表明，不同群体龙头鱼在形态上存在一定差异，躯体长度、臀鳍位置和头部形态是区分它们的主要特征，但这些差异与地理分布没有形成对应关系。推测不同群体间频繁的交流使得形态差异受地理距离的影响较小，环境因子可能是导致特征差异的主要原因。

Multivariate analysis of Harpadon nehereus populations from coastal areas of China based on morphological characters

To investigate the morphometric differentiation of Harpadon nehereus from coastal areas of China, multivariate mathematical-statistical analysis of 29 meristic characters (199 individuals) of eight H. nehereus populations were conducted by traditional morphological and geometric framework methods. Principal component analysis (PCA) was used to construct seven principal components (PC), with a cumulative contribution ratio of 71.481%. The scatter-plot of the principal components showed that the characteristics of the Zhoushan and Chaozhou populations were different from the others. PC1 reflected differences in the anal fin size and the oblique distance of fish body between the ventral and anal fins. PC2 accounted for the distance between the eyes and the mouth crack length. A one-way analysis of variance (ANOVA) indicated no significant differences in the mouth crack length/head length (MCL/HL), the origin of the adipose fin to the origin of the pelvic fin/body length (D₃-D₈/BL), the origin of the anal fin to the origin of the dorsal fin/body length (D₅-D₆/BL), or the terminus of the anal fin to the terminus of the adipose fin/body length (D₇-D₁₀/BL). Phylogenetic analyses showed that the Zhoushan population clustered in the outermost layer of the tree, followed by the Haikou and Qingdao populations. Stepwise regression analysis was used to select 9 character values of the greatest effects to establish the discriminant formula. The discriminating accuracy of the Qingdao population was 100%, and the comprehensive discrimination rate was 66.9%. The results showed there were some morphological differences among different populations of H. nehereus. The body length, anal fin position and head shape were the dominant characteristics to distinguish them. However, these differences had no corresponding relationships with geographical distribution. It was speculated that the frequent communication between different populations made the morphological differences less affected by geographical distance, and environmental factors may be the main reason.