Preference of Trichodinids (Ciliata, Peritrichia) occurring on fish-pond carp for particular organs and some morphological implications

Abstract

The present study describes the preference of Trichodinids for skin or gills of fish-pond carp. Differences in localization of trichodinids were analysed by the Mann-Whitney U and Χ 2 tests. For histological examination gills were fixed in 4% formaldehyde and processed using standard techniques. Trichodinella epizootica and T. subtilis parasitised exclusively gills. The occurrence of Trichodina acuta was far more frequent on the skin and that preference appeared to be statistically significant. Trichodina nobilis was found on both skin and gills with a significant preference for skin; Trichodina nigra was found on both target organs. Trichodinella epizootica damaged the gill epithelia and induced enforced mucous secretion.