Introduced and Globally Invaded Polychaetous Annelids

Abstract

Recently much attention has been devoted to the introduction of foreign organisms into marine and estuarine communities. Among many marine alien invertebrates in Japanese waters, only four species of polychaete are known as introduced species. In the world, 74 species of polychaete belonging to 15 families have been revealed as introduced or cryptogenic species. Among them, Spionidae, Sabellidae, Serpulidae (including Spirorbinae), and Nereididae are the most frequently reported. These families are found on the shells of introduced oysters, scallops, and other commercially important mollusks, and also on algae. The main introduction vectors are ballast water and fouled ships. Additionally, some species imported and exported as "fishing bait worms" have possibly settled successfully at non-native localities. We summarize here the worldwide invasion of polychaetes and discuss the ongoing problems concerning them.