Protection of goldfish against some common ectoparasitic protozoans using Ichthyophthirius multifiliis and Tetrahymena pyriformis for vaccination

Abstract Goldfish ( Carassius auratus ) were vaccinated with live tomites of Ichthyophthirius multifiliis (Fouquet) and Tetrahymena pyriformis (Lwoff) by immersion or intraperitoneal injection. They were then challenged with I. multifiliis and some other common ectoparasitic protozoans, such as Oodinium pillularis (Schaperclaus), Ichthyobodo necatrix, Chilodonella cyprini , and Trichodina sp. Results indicated that goldfish vaccinated with either I. multifiliis or T. pyriformis developed protective immunity not only against the I. multifiliis but also towards other ectoparasitic protozoans which are commonly found in the tropics. The results also showed that the protection was correlated with the antibody titers in their plasma and skin mucus.