Definitive hosts: this species is known to infect over 30 different species of fish eating mammals, including canids, felids, mustelids, bear, and humans. Some birds may also harbor adult worms.
Site of infection: crypts of the small intestine
Typical size: 1-2.5 mm long x 0.3-0.5 mm wide
Distribution: North Pacific basin
First intermediate host: in North America, the snail Oxytrema silicula is the common host. Only redial generations have been found
Metacercariae: metacercariae develop throughout the body of a in variety of fish species, although salmonids are the most common hosts. Infections can be quite heavy, and fish mortality may result
Other: the fluke may carry Neorickettsia helminthoeca, the agent of salmon poisoning in canids