Heligmosomoides bakeri: a new name for an old worm?

A popular model system for exploring the host–parasite relationship of gastrointestinal nematodes is commonly known as Heligmosomoides polygyrus bakeri. Recently, this parasite was raised to full species level as H. bakeri, to distinguish it from a close relative, H. polygyrus sensu stricto, the dominant intestinal nematode of wood mice in Western Europe, which is unable to infect laboratory mice (Mus sp.) without the aid of powerful immunosuppressants. Herein, the argument is presented that it is necessary to rename this parasite, and that H. bakeri is the correct name for the species used widely throughout the world as a laboratory research model. Supporting this claim, key evidence is presented demonstrating that H. bakeri and H. polygyrus are two quite distinct species.