in taxon Trypanosomatidae promastigote stage Jie Zheng Chris Stoeckert Priti Parikh A parasite lifecycle stage of Trypanosomatids. In this stage, the flagellum is found anterior of nucleus and flagellum not attached to the cell body. The kinetoplast is located in front of the nucleus, near the anterior end of the body. (Wikipedia: Trypanosomatid) parasite lifecycle stage