There are several phyla of protozoa that locomote by flagellae. Many of these types of flagellates are not very closely related, but in this section you will see some different types of flagellates.
Prepare a stained slide of flagellates found in termite guts, and try to identify the major parts of the organisms - particularly the flagellae. Your instructor will demonstrate the procedure, Be sure to handle the termites very carefully. The staining procedure is relatively simple, but it is extremely important that the flagellate organisms are not allowed to dry out during the procedure described on the lab bench, and you must be careful to keep track of which side of the coverslip the organisms are attached.
Trypanosoma lewisi (Rust, fig. 13 d-f; C & V fig. 4.15) - Members of Trypanosoma include species that cause African Sleeping Sickness upon being transmitted by the blood sucking tse-tse fly. Another species, T. cruzi, causes Chagas' disease in South America (Charles Darwin contracted the disease during his voyage), and is transmitted to its mammalian host by the bite of an assassin bug. Trypanosomes establish themselves in the blood stream where they grow and reproduce. Examine a stained blood film of a mouse infected with Trypanosoma lewisi and locate the trypanosomes that are located in the blood plasma between erythrocytes. What is their approximate size? A mammalian erythrocyte is approximately 7 µm in diameter. Notice the nucleus. Also, near the base of the flagellum there is a structure which stains in a similar manner to the nucleus. This is the kinetoplast. The kinetoplast is a part of the mitochondrion of the trypanosome which contains a relatively large amount of DNA. This is why it stains like the nucleus. This may be your only opportunity to observe mitochondrial DNA based on its staining characteristics. Mitochondria of eukaryotes contain DNA, but the amount present is too small to provide for a stained image. Notice the flagellum which is associated with the side of the trypanosome to form a wavy, undulating membrane.