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为阐明太平洋鲱和大西洋鲱种间形态上的差异,应用单因子方差分析、聚类分析和判别分析方法对两种鱼的23个形态学参数进行了研究。单因子方差分析结果表明:14个形态参数平均值存在极显著差异(P<0.001),且种群间差异大于种内差异。聚类分析结果显示所有82个个体明显聚成两支。所有23个形态参数的判别分析结果表明,两种间的形态差异极显著(P<0.001);利用挑选后的11项参数判别分析,得出判别等式,两种鱼间的形态差异仍然极显著(P<0.001),判别准确率100%。所有23个形态参数的差异系数全部小于Mayr的75%法则临界值,表明两个种间形态学上虽然存在一定分化,但分化程度尚未达到亚种水平。作者推测两个种间形态上低水平的分化可能由于分化的时间较短以及相似的生活环境造成的。
To clarify the morphological differences between herring and Atlantic herring, one-way ANOVA, cluster analysis and discriminant analysis were used to study the 23 morphological parameters of two species of fish. One-way analysis of variance showed that there was significant difference (P <0.001) in the average value of 14 morphological parameters, and the difference among the populations was greater than the intraspecific difference. Cluster analysis revealed that all 82 individuals clearly clustered into two. The discriminant analysis results of all 23 morphological parameters showed that the morphological differences between the two species were significant (P <0.001). Using discriminant analysis of eleven parameters after selection, the discriminant equation was obtained. The morphological differences between the two species of fish were still significant (P <0.001), the discrimination accuracy rate of 100%. The difference coefficients of all 23 morphological parameters were all less than Mayr’s 75% rule critical value, indicating that although the morphological differences existed between the two species, their differentiation did not reach the level of subspecies. The authors speculate that the low level of morphological differentiation between the two species may be due to the shorter period of differentiation and similar living conditions.