This is a gallery of fish pathogen videos. Many pathogens will actively move in water to seek or attract their next host.

Clinostomum
Anisakis nematodes
Anisakis nematodes
"Rattenkoenig" cercaria
Trematode cercaria
Trematode cercaria
Trematode cercaria
Camallanus nematode
Gyrodactylus on gill
Whirling disease in rainbow trout
Whirling disease in rainbow trout
Proteocephalus tapeworm
Proteocephalus tapeworm
Gyrodactylus on gill
Snail releasing cercaria