Observations on the food and the gut pigment of the Polyopisthocotylea (Trematoda: Monogenea)

It has been shown by spectroscopic and histochemical methods that eight representative species of Polyopisthocotylea feed mainly on the blood of their hosts. 2. The blood is probably haemolysed fairly rapidly and subsequently absorbed by amoeboid ingestion, the globin moiety of the haemoglobin forming the chief nutriment of the parasite and the unaltered haematin being eliminated either by its discharge from epithelial cells into the gut lumen or by the sloughing off of intact epithelial cells. 3. In a more limited sample of skin-and cloaca-inhabiting Monopisthocotylea there was no evidence of a blood-feeding habit.