The acorn barnacle is a common invasive species, found on Pacific coasts. (Shutterstock) June 2, 2020 Predator snails fend off the invasion of barnacles in Japan Julius A. Ellrich, St. Francis Xavier University and Takefumi Yorisue, University of Hyogo Barnacles are an invasive species, carried worldwide along shipping routes. But Japan has a local solution: predatory and herbivorous snails feed on the barnacles and limit their spread.