The rapa whelk, Rapana venosa, is a large predatory gastropod native to the Sea of Japan, Yellow Sea, East China Sea and the Bohai Sea. It was introduced into the eastern Black Sea some time in the 1940 and subsequently spread around the Black Sea before entering the Aegean Sea. Its current distribution in the Mediterranean Sea extends as far west as the western coast of Italy. Rapana was discovered in the southern Chesapeake Bay in 1998. The suspected vector is ballast water transport of larval stages with returning vessels employed in a coal trade with Black Sea ports. The species is now established in the southern Chesapeake Bay, and over 20,000 have been collected in a 10-year period as part of collaborative program with local watermen. Genetic evidence suggest that the more recent discovery of Rapana in the Rio del Plata in Argentina may have originated from populations in Hampton Roads. Locally collected Rapana are the largest of any present in native and non native populations, often approaching 175mm maximum dimension.