The eggs are ingested by its next host, the snail Potampyrgus antipodarum. Inside the snail, the eggs hatch and develop into cercariae. Free-swimming cercariae leave the snail and encyst in the skin or flesh of Galaxias anomalus, which act as secondary intermediate hosts. Metacercariae in flesh or skin of the small fish are then ingested by an eel completing the transmission cycle. Pathology Telogaster opisthorchis can be diagnosed by examining the outer appearance of the host. Generally, the metacercariae of T. opisthorchis will result in characteristic spinal and fin abnormalities that can be observed in the late larval and early juvenile stages of the host. In addition, some other Galaxias species also experience head and jaw disfigurements. At times, metacercarial cysts may also be observed through the skin of the host. The cysts are seen as mini, white colored bumps that are approximately 1mm in diameter. Currently, there is no treatment for T. opisthorchis. Vector control of first intermediate hosts is the only viable option towards combating T. opsithorchis. References Heterophyidae Endoparasites