“…In this study, we questioned recreational fishers about a conspicuous alien crustacean, which has the characteristics to capture people's attention and be easily remembered by the respondents: the Atlantic blue crab Callinectes sapidus (Rathbun, 1986). The Atlantic blue crab is a shelf-estuarine species originally distributed in the Eastern coasts of North America, which was introduced in Europe through ballast waters (Bouvier, 1901;Mancinelli et al, 2017a), where it progressively expanded from the Atlantic area, to the Mediterranean and the Black Seas (Mancinelli et al 2017b;Suaria et al, 2017). Despite local evidences highlighting competitive interactions with native species (Gennaio et al, 2006;Mancinelli et al, 2013) and impacts on smallscale fisheries (Fuentes et al, 2019;Kampouris et al, 2019;Nehring, 2011;Perdikaris et al, 2016;Ventura et al, 2018), the ecological and economic consequences of this invasion have been poorly assessed and our understanding of the species distribution is largely limited to occasional observations (Mancinelli et al, 2017c.…”