CULTIVATION OF BLOOD-STREAM FORMS OF TRYPANOSOMA-CARASSII, A COMMON PARASITE OF FRESH-WATER FISH

Trypanosoma carassii (syn. T. danilewskyi) is a widespread parasite of carp and other cyprinid as well as some noncyprinid freshwater fish. It lives extracellularly in the blood and tissues of its hosts, causin g chronic infections. In this paper the isolation of T. carassii from fish blood and the propagation and cloning of bloodstream forms in vit ro are described. By several criteria, cultured and fish-derived trypo mastigotes are indistinguishable. The culture system should be useful for the biochemical characterization of this trypanosome and its inter action with the fish immune system.