The Mediterranean Sea, one of the most complex marine ecosystems, is inhabited by a rich and diverse biota which is disproportionate to its dimensions. It is currently affected by different pressures, mainly driven by human activities such as climate change and bioinvasions. This Sea, also due to its geographic position (wedged between the temperate climate of central Europe and the arid climate of northern Africa), seems to be one of the regions most susceptible to global climate change. The increased rates of introduction and spread of marine alien species may represent a supplementary stress factor to Mediterranean marine native biota already challenged by climatic abnormalities. The Suez Canal is considered to be the main vector of introduction of non‐indigenous marine species into the Mediterranean Sea. Due to the dramatically accelerating rate of such introductions and due to the sheer magnitude of shipping traffic, the Mediterranean Sea may be considered as a true hotspot of marine bioinvasions. The complexity of interactions between native and invasive species and the associated resulting impacts make environmental management of such an issue particularly difficult. A collaboration between researchers, resource management agencies and policy makers is called for to bolster the effectiveness of invasive species management procedures.

The lowfin chub, Kyphosus vaigiensis, is reported for the first time off Favignana Island, Sicily, central Mediterranean Sea. The specimen was identified on the basis of morphometric and meristic characters as well as mitochondrial DNA sequences (COI and 16S-rDNA). Two, perhaps three, Kyphosus species—K. bigibbus, K. sectatrix and K. vaigiensis—have been occasionally recorded in the Mediterranean. These species occur both in the Atlantic and Indo-Pacific regions but it is likely they entered the Mediterranean through the Strait of Gibraltar. However, it is unclear whether they have established reproductive native populations in the Mediterranean.

Biological invasions are widely recognized as a major threat to native biodiversity, ecosystem functioning and services. Amongst the NIS recorded in the Mediterranean Sea, Chlorophyta species belonging to the genus Caulerpa (Caulerpa cylindracea, C. taxifolia and C. taxifolia var. distichophylla) have raised serious concerns due to their potential or ascertained impact on native benthic communities. During surveys carried out to monitor the occurrence and the coverage of Caulerpa species along the coasts of Favignana Island (Egadi Islands Marine Protected Area), we observed variations in C. cylindracea and C. taxifolia coverage and also some large invertebrates overgrown with thalli of both species.