Abstract
Oncomiracidia of the gill monogenean Heterobothrium okamotoi experimentally attached to both the body surface and gills of tiger puffer Takifugu rubripes. While worms disappeared from the body surface in 3 days, those on the gills showed an increase in number in 12 days. When worms were removed from the body surface with a formalin treatment, such an increase was not observed in worms on the gills. Naïve fish became infected, when cohabiting with fish just after challenge, although they were separated with a mesh screen. These results demonstrate that H. okamotoi can reinfect new hosts after detachment from the body surface of previous hosts.
