the western Mediterranean and the western Atlantic Bayha et al. (Bayha et al., 2004) concluded that Beroe ovata sensu Mayer, 1912, which seemed to be restricted to the eastern seaboard of North and South America, much like M. leidyi, was then introduced into the Black Sea. So, these authors use Beroe ovata sensu Mayer, 1912 as the species name.