Off the western coast of Mexico, anglers hauled in their catch and began the process of taking the fish to a nearby market. Something in the fish's mouth caught their attention - and for good reason.

Allison Little, a middle school assistant principal from Anchorage, has been fishing on the Kasilof River her entire adult life, so she’s used to seeing wormy parasites coiled up in fish on occasion.

Monogenean parasites represent a significant challenge to aquaculture operations, particularly affecting finfish by infecting the skin and gills. These ectoparasitic flatworms are characterised by ...