A novel Kunitz protein with proposed dual function from Eudiplozoon nipponicum (Monogenea) impairs haemostasis and action of complement in vitro

•Eudiplozoon nipponicum extract inhibits some peptidases involved in haemostasis/fibrinolysis.•EnKT1 Kunitz protein inhibits Factor Xa, plasmin and plasma kallikrein.•Recombinant EnKT1 significantly impairs both haemostasis and complement activation in vitro.•Secretory EnKT1 may facilitate blood digestion and protect the parasite’s gastrodermis.•EnKT1 is the first parasite Kunitz protein known to affect the host’s complement.