不同产地中华绒螯蟹形态差异的地标点法分析

为了解长江水系的太湖、洪泽湖、高宝湖、长荡湖、阳澄湖以及巴城、兴化"泓膏"养殖水域和长江口崇明自然水域等知名产区产中华绒螯蟹形态上的差异,首次运用地标点法研究其形态的产地差异性。背甲以及腹甲的形态使用地标点法进行分析,经图像处理后提取地标点坐标,进行相对扭曲主成分分析以及判别分析,利用薄板样条分析和网格变形将其形态变异矢量可视化。结果显示,在相对扭曲主成分分析中,提取了许多Ⅱ型地标点,其贡献率为82.637%~97.698%,作用较大,解释了主要形态变异。特别是相对扭曲主成分的判别分析对雄性以及雌性蟹背甲的判别准确率均为100%。研究表明,不同产地养殖环境可以导致中华绒螯蟹的形态出现差异;而以背甲为对象的形态地标点法分析应该可以作为判别不同产地中华绒螯蟹的有效方法。

Landmark-based morphometric identification of different geographical origins for the Chinese mitten crab (Eriocheir sinensis)

Landmark-based morphometric analysis was conducted to identify variations in Chinese mitten crab Eriocheir sinensis from different well-known geographical origins around the same Changjiang River system, e.g., the Taihu Lake, Hongze Lake, Gaoyou Lake, Changdang Lake, Yangcheng Lake, Bacheng Aquaculture Water, Xinghua "Honggao" aquaculture area, and Chongming waters. Landmark coordinate values were extracted by image processing after digitalization of the carapace and the breastplate features, thereafter, processed with relative warp principal component methods, discrimination analysis, thin plate spline analysis and grid distortion. Many of the Type Ⅱ landmarks were extracted by relative warp principal component analysis and they had important contributions (82.637%–97.698%) in explaining the most important variation. The discrimination analysis indicated that the carapace of male and female had exactitude distinguishing ratios of 100% while the breastplate had exactitude distinguishing ratios of 98.75% and 83.75%, respectively. All of these indicated that it was an effective method of habitat recognition of Chinese mitten crab by using landmark-based morphometric analysis, which provides some important reference and scientific basis for developing a more objective method for geographical origin identification of E. sinensis.