We conducted comprehensive analysis of gut contents in three Opisthorchiidae species.
Gut lumen of Opisthorchis felineus and Clonorchis sinensis contains hemozoin crystals.
Biocrystallisation of hemozoin takes place on the surface of lipid droplets.
Hemozoin is not present in the gut of Opisthorchis viverrini.
Opisthorchis felineus and C. sinensis are blood-feeding parasites.