Nematodes are relatively large parasites that can occur in the digestive system, internal organs and periodically in the muscle tissue and fins of fish (some species).
Microscopic videos
Flagellates in discus – video
Parasites of the digestive system and internal organs – flagellates
Flagellates Hexamita and Spironucleus are protozoa, which, due to the characteristic way of their moving up is relatively easy to identify under the microscope.