Trypanosoma cruzi trypomastigote

The trypomastigote stage of Trypanosoma cruzi swims in the blood of its mammalian host. This species is recognized by its characteristic "c" shape.

In this photo the trypomastigote is located between two host erythrocytes. The nucleus is large and is located towards the bottom of the photo. The smaller, densely-staining kinetoplast is at the opposite end, towards the top of the photo. The flagellum is not visible in this photo, but would arise near the kinetoplast, pass internally towards the nucleus, and emerge as a free flagellum at the end opposite the kinetoplast. While internal, the flagellum would raise the pellicle and form an undulating membrane.