Vignon Matthias, Sasal Pierre
UMR 5244 CNRS EPHE UPVD, Biologie et Ecologie Tropicale et Méditerranéenne, Université de Perpignan Via Domitia, Perpignan cedex, France.
Parasitol Int. 2010 Jun;59(2):183-91. doi: 10.1016/j.parint.2010.01.006. Epub 2010 Feb 1.
The sclerotized attachment organ of monogeneans has been widely used to address fundamental questions in ecology and evolution. However, traditional morphometric techniques appear to be partially inadequate and non-optimal. Traditional linear measurements mainly provide information on the size of sclerites but provide very little information, if any, on their shape. The shape of sclerites is indeed virtually unexplored and its implication for ecological and evolutionary processes remains to be analyzed. This study aims to both introduce and illustrate the use of geometric morphometrics in order to study sclerites of monogeneans in a biogeographic context. To do this, we investigated morphological variation patterns among four populations from the Pacific Ocean and six monogenean species through traditional and geometric morphometric techniques. Unlike the traditional method, the geometric morphometric method yielded a high percentage of individuals correctly classified to the four populations, providing strong evidence for phenotypic variability, divergence and local adaptation among islands without evolutionary constraint. Moreover, the traditional method also resulted in inconsistent interpretations of shape variations. This study highlighted the limitations that may arise when using traditional morphometric techniques and emphasizes that considerable information about the shape of sclerotized haptoral parts is added by using geometric morphometrics. Given the prominent taxonomic, ecological and evolutionary role of the haptor for characterizing monogeneans, we ultimately discuss the potential broad use of geometric morphometrics in a wide variety of ecological and evolutionary contexts. This powerful approach might allow a more robust estimation of the extent to which traditional evolutionary theories based on size of sclerites are congruent with their shape.
单殖吸虫的硬化附着器官已被广泛用于解决生态学和进化方面的基本问题。然而，传统的形态测量技术似乎部分不足且并非最优。传统的线性测量主要提供关于骨片大小的信息，但对于其形状提供的信息极少，即便有也微乎其微。骨片的形状实际上几乎未被探索，其对生态和进化过程的影响仍有待分析。本研究旨在介绍并阐明几何形态测量学的应用，以便在生物地理学背景下研究单殖吸虫的骨片。为此，我们通过传统和几何形态测量技术研究了来自太平洋的四个种群和六个单殖吸虫物种之间的形态变异模式。与传统方法不同，几何形态测量法对个体正确分类到四个种群的比例很高，为岛屿间无进化限制情况下的表型变异性、分歧和局部适应性提供了有力证据。此外，传统方法对形状变异的解释也不一致。本研究突出了使用传统形态测量技术可能出现的局限性，并强调使用几何形态测量学能增加关于硬化吸附器部分形状的大量信息。鉴于吸附器在单殖吸虫分类、生态和进化特征描述方面的突出作用，我们最终讨论了几何形态测量学在各种生态和进化背景下的潜在广泛应用。这种强大的方法可能会更有力地估计基于骨片大小的传统进化理论与其形状的相符程度。
