Ornamental Fish Q&A 19

This question was provided by Manson Publishing as part of the OVAL Project. See more Ornamental Fish Q&A.

These rapidly spinning ciliated organisms were seen on the examination of a skin scrape (×100).

Question	Answer		Article
Name the organism.	Trichodina, a ciliated protozoan parasite which is a common cause of skin and gill disease in ornamental fish.		Link to Article
How is a skin scraping prepared?	A skin scrape is prepared by obtaining a small quantity of mucus from the skin surface of a freshly dead or anesthetized fish. Areas of predilection for skin parasites are those adjacent to the fins and it is a good approach to obtain material from these sites. The mucus is suspended in a small quantity of water on a microscope slide (preferably pond or tank water from which the fish was taken; tape or distilled water may destroy the parasites), a cover slip applied, and the preparation examined under the microscope (×40 magnification should be sufficient to visualize most parasites). The second picture shows prepared gill, fin, and skin biopsies.		Link to Article