What is common about Trypanosoma. Noctiluca, Monocystis and Giardia?

Trypanosoma gambiense is the single celled, parasitic zoofiagellate causing trypanosomiasis or sleeping sickness. Giardia is a parasitic flagellate occurring in the intestine of man and other animals and causes giardiasis or diarrhoea (i.e., very loose and frequent stool containing large quantity of fat). Noctiluca is a marine, colourless dinoflagellate. It is a voracious predator and has a long, motile tentacle, near the base of which, its single short flagellum emerges. Monocystis is a microscopic, unicellular endoparasitic protozoan found in the coelom and seminal vesicles of earthworm. As it is an endoparasite, it does not possess any special structure for locomotion.