Since the end of the last century, the number of new macrophytic algae introduced in the Mediterranean basin is steadily increasing. Among them, Caulerpa cylindracea is now locally established, and considered invasive. In this study, we hypothesized that the presence of C. cylindracea on hard substrates may influence macrozoobenthos communities; to test it we used a multivariate model to compare several samples from the Pelagie Islands MPA (Lampedusa, Italy) in which the alien alga was present. Samples were collected in two sites in November 2013 by scuba divers using a standard airlift sampling device and by scraping macrobenthic species. Statistical analysis highlighted that C. cylindracea was the only algal species affecting significantly the macrozoobenthos communities. Our analyses also show that the taxonomic groups Amphipoda, Caridea, Tanaidacea are related with higher presence of C. cylindracea, while Sipuncula, Nematoda and Polychaeta are correlated with native algae. We conclude that C. cylindracea attracts this benthic fauna by creating an extension of both trophic and edaphic niches. Moreover, the study shows that C. cylindracea affects the diversity of the macrozoobenthos at a state of dispersion dynamics where the alga is intermixed with other algae and not when it is dominant.

自上世纪末以来，地中海盆地引入的新的大型植物藻类数量一直在稳步增加。其中，Caulerpa cylindracea现在已在当地建立，并被认为具有侵入性。在这项研究中，我们假设硬质底物上的C. cindindracea的存在可能会影响大型动物。为了测试它，我们使用了一个多元模型来比较来自存在外来藻类的Pelagie Islands MPA（意大利Lampedusa）的几个样本。2013年11月，水肺潜水员使用标准的气举采样装置并通过刮除大型底栖动物，在两个地点采集了样本。统计分析突出显示C. cindindracea是唯一会严重影响大型动物的藻类。我们的分析还表明，两类分类群：两栖纲，Caridea，Tanaidacea与C. cindindracea的较高存在有关，而Sipuncula，Nematoda和Polychaeta与天然藻类有关。我们得出的结论是，C。cindindracea通过创造营养和生态位的延伸而吸引了这种底栖动物。此外，研究表明，在藻类与其他藻类混合而不是占优势的分散动力学状态下，C.cylindracea会影响大型动物的多样性。