Range expansion of the common lionfish Pterois miles (Bennett, 1828) in the Mediterranean Sea: an unwanted new guest for Italian waters.

Lionfishes are conspicuous and disruptive predators once introduced outside of their native range. Here we provide a revision of the occurrences of the common lionfish Pterois miles (Bennett, 1828) in the Mediterranean Sea, showing its rapid geographical expansion since 2012. A single lionfish was photographed in September 2016 during a scientific survey off the Vendicari coast, Southern Sicily, Italy. This is the first record of this notorious invasive species from Italian waters. Given its large size, conspicuous appearance, and venomous spines, it is critical to involve informed citizen scientists in tracking the spread of this species and to develop means to manage or adapt to its presence in the Mediterranean Basin.