Immunity to Amoeba

•We review immune response of fish to amoebic infections.•Little information is available for most amoebic infections.•Amoebic Gill Disease (AGD) in Atlantic salmon is most studied.•We focus our review on AGD.

Amoebic infections in fish are most likely underestimated and sometimes overlooked due to the challenges associated with their diagnosis. Amoebic diseases reported in fish affect either gills or internal organs or may be systemic. Host response ranges from hyperplastic response in gill infections to inflammation (including granuloma formation) in internal organs. This review focuses on the immune response of Atlantic salmon to Neoparamoeba perurans, the causative agent of Amoebic Gill Disease (AGD).