One objective of invasion biology is to understand the lagphase of when a species arrives in a new environment. Considering that it must first reach the new system before it can be documented, a lapse in time will always exist between the first entrance of an invader and its subsequent discovery (Crooks, 2011). Nevertheless, in some cases such as the bluespotted cornetfish Fistularia commersonii, the first detection of the species in 2000 (Golani, 2000) was concurrent with the beginning of the invasion, without an apparent lag between the first documented arrival, subsequent establishment, and ecological integration (Azzurro et al., 2012). Fistularia commersonii Rüppell, 1838 was originally distributed in the Indian and Pacific oceans (Fritzsche, 1976). Today it is considered one of the most successful invaders of the Mediterranean Sea and Europe (Streftaris and Zenetos, 2006; DAISIE, 2008) and has received much scientific attention (eg Kalogirou et al., 2007; Bariche et al., 2009, 2013; Bariche and Kajajian, 2012). Genetic studies have highlighted a severe population bottleneck, resulting in a reduced genetic diversity in the Mediterranean (Golani et al., 2007; Sanna et al., 2011).