Invasive seaweeds threaten biodiversity and socio-economics values of worldwide marine ecosystems. Understanding to what extent invasive seaweeds can modify local biodiversity is one of the main priorities in conservation ecology. We compared the molluscan assemblage of the invasive Asparagopsis taxiformis with that of the native Ericaria brachycarpa and explore if variation in the molluscan assemblage diversity was related to the substrate attributes (biomass, and thallus, canopy, and interstitial volumes) of the algae. Results showed that A. taxiformis harboured lower diversity and trophic structure of the molluscan assemblage compared to E. brachycarpa. Biomass was the variable that better explained the variation of abundance and number of species as well as the multivariate structure of the molluscan assemblage. Overall, our results suggest that a complete habitat shift from native to invasive species can potentially trigger bottom-up effects in rocky shores habitats, reducing the biodiversity and the services provided by the invaded habitat.

入侵性海藻威胁着全球海洋生态系统的生物多样性和社会经济价值。了解入侵性海藻在多大程度上可以改变当地的生物多样性，是保护生态学的主要优先事项之一。我们比较了侵​​袭性天冬虫的软体动物组合与原生短穗Ericaria brachycarpa的软体动物组合，并探讨了软体动物组合多样性的变化是否与藻类的底物属性（生物质，th体，树冠和间质体积）有关。结果表明，相比于短叶大肠杆菌，出租车种的软体动物群落具有较低的多样性和营养结构。。生物量是一个变量，可以更好地解释软体动物种群的丰度和物种数量以及多元结构的变化。总的来说，我们的研究结果表明，从原始物种到入侵物种的完全栖息地转变可能会在多岩石的海岸栖息地引发自下而上的影响，从而减少生物多样性和入侵栖息地提供的服务。