The increasing trend of biological invasions is one of the most concerning threats for ecosystems functioning. The identification of optimal characters determining the invasive potential of non-native species has always been a challenge in conservation studies. Morphological features can be used as a good proxy to address the invasive success in fish species, assuming that anatomical differences in comparison to native species can provide to newcomers ecological opportunities increasing their probability to become successful. Considering this, the present study constitutes the first applicative attempt of a model based on geometric morphometrics to demonstrate the importance of the carapace shape in the invasive ability in marine decapod crustaceans. The study was performed on the native brachyuran community of Alfacs Bay, in the Ebro Delta, the largest estuarine zone along the north-western Mediterranean, in which two recently established non-native crab species coexist: Dyspanopeus sayi and Callinectes sapidus. Results suggested that invaders with extreme carapace traits located peripherally in the community morphospace, such as C. sapidus, usually possess ecological advantages contributing to understand their success. Conversely, intermediate morphologies within the morphospace, such as D. sayi, imply ecological overlapping with native species reducing their community relevance. Besides, we also assessed the effect on the community morphospace of a hypothetical future invasive event from another crab species (Portunus segnis) with high probabilities to also colonize the community. Our outcomes confirm that the morphometric approach could be an alternative tool for assessing the potential ability of invasive crab species. However, further studies at different spatial and temporal scales, including additional traits and quantitative data from invasions, would be necessary to confirm the efficacy and usefulness of the methodology.

生物入侵的增加趋势是对生态系统功能最令人担忧的威胁之一。在保护研究中，确定决定非本地物种入侵潜力的最佳特征一直是一项挑战。假设与本地物种相比的解剖学差异可以为新移民提供增加其成功可能性的生态机会，则形态特征可以用作解决鱼类入侵成功的良好替代。考虑到这一点，本研究构成了基于几何形态计量学的模型的首次应用尝试，以证明甲壳形状在海洋十足纲甲壳类动物的侵袭能力中的重要性。这项研究是在埃布罗三角洲的Alfacs湾本地brachyuran社区进行的，dyspanopeus sayi和Callinectes sapidus。结果表明，具有极端甲壳特征的入侵者位于群落形态空间的外围，例如C. sapidus，通常具有有助于了解其成功的生态优势。相反，形态空间内的中间形态，例如D.sayi，意味着与本地物种的生态重叠会降低其社区相关性。此外，我们还评估了另一种蟹类物种（Portunus segnis）未来假性入侵事件对群落形态空间的影响。）也很有可能在社区中殖民。我们的结果证实，形态计量学方法可能是评估入侵蟹种潜在能力的替代工具。但是，有必要进一步进行不同时空尺度的研究，包括入侵的其他特征和定量数据，以确认该方法的有效性和实用性。