Tylodelphys

[2] Other species of flukes are able to turn into dormant cysts at certain stages of development, but Tylodelphys spp.

stays active and roams free inside the fish's eye, giving it an opportunity for it to induce parasite behavior.

has a complex three-host life cycle, with a variety of fish- and amphibian-eating birds and lymnaeid or planorbid gastropods as first intermediate hosts.

Tylodelphys species can also infect the brain or the body cavity of their second intermediate hosts, which are typically fish but sometimes amphibians.

metacercariae may limit the bully's ability to perceive visual cues of predatory threat by obscuring vision during the day, in a similar manner to Diplostomum induced cataracts, favoring completion of the trematode's life cycle.