First finds in North and South America of Pentacoelum kazukolinda (Platyhelminthes: Tricladida), a worldwide invasive flatworm

Invasive species form an important threat to autochthonous biodiversity and ecosystems, as they may negatively affect native species. Pentacoelum kazukolinda is an invasive maricolan flatworm with a freshwater ecology that was already known to be widely distributed in the Northern hemisphere: USA (Hawaii), Spain, Germany, The Netherlands, and Japan. Here we detail the first records from Chile, Peru, and continental USA. These new records from North and South America were substantiated by observations on the very characteristic external appearance of the specimens, their anatomy, and/or molecular data. We demonstrate for the first time that the animals are capable of regeneration. At the newly discovered localities in South America, this flatworm co-occurs with introduced snails, which may constitute its prey species, and with introduced aquatic plants that may have facilitated its introduction into the New World.