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根据2011年6-8月我国拖网船在摩洛哥南部沿岸采集的46尾金色小沙丁鱼(Sardinella aurita)和53尾沙丁鱼(Sardina pilchardus)的耳石样本,利用传统形态测量法和傅立叶分析法分别进行分析,对不同的耳石形态进行判别。传统形态测量法测量了6个耳石形态参数,并利用t检验比较两种沙丁鱼耳石形态差异;耳石轮廓经图像化处理后利用软件转化为椭圆傅立叶标码(EFDs),最后分别采用6个耳石形态参数和标准化后的77个傅立叶系数进行主成分分析和判别分析。结果表明,两种沙丁鱼耳石形态在全长(TL)、宽度(TW)、背宽(DW)、腹噱长(VL)中存在显著差异(P<0.01),背长(DL)和翼叶长(WL)不存在差异(P>0.05);主成分分析表明,传统测量法的前两个主成分累积贡献率达77.0%,第一、二主成分的最高变量分别为全长(TL/FL)和背宽(DW/FL),在散点图中显示出了很好的区分性;而傅立叶分析法中,前16个主成分累积贡献率为82.8%,前两个主成分因子仍有较大的重叠,区分性相对较差。判别分析结果认为,传统测量法中的3个参数值进入了逐步判别分析中,总判别正确率为83.76%;傅立叶分析法的77个傅立叶系数中,有9个系数进入了逐步判别分析中,总判别正确率为92.02%。总体来看,相比传统形态测量法,傅立叶方法在鱼类耳石的判别分析中更为有效。
According to the otolith samples of 46 Sardinella aurita and 53 Sardina pilchardus collected from the trawler in the southern coast of Morocco from June to August in 2011, the morphological measurements and the Fourier analysis were used to analyze the otolith samples respectively , To determine the different otolith morphology. Six morphological parameters of otolith were measured by traditional morphometric method and t-test was used to compare the morphological differences of two kinds of sardines. The images of otolith were converted to elliptic Fourier-coded (EFDs) images by software. Finally, A otolith morphological parameters and standardized 77 Fourier coefficients for principal component analysis and discriminant analysis. The results showed that there were significant differences in TL, TW, DW and VL among two sardine otoliths (P <0.01) The principal components analysis showed that the cumulative contribution rate of the first two principal components of the traditional measurement method reached 77.0%, the highest variables of the first and second principal components were the total length (TL) / FL) and back width (DW / FL) showed a good distinction in the scatter plot. In the Fourier analysis, the cumulative contribution rate of the first 16 principal components was 82.8%. The first two principal component factors There is still a large overlap, the distinction is relatively poor. According to the results of discriminant analysis, the three parameters of the traditional measurement method enter the stepwise discriminant analysis, the total discriminant accuracy rate is 83.76%. Of the 77 Fourier coefficients of Fourier analysis, 9 coefficients enter the stepwise discriminant analysis, The total discriminant accuracy rate was 92.02%. In general, the Fourier method is more effective in the discriminant analysis of otoliths than traditional morphometric methods.